diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/workreports/daos/WorkReportTypeDAO.java b/navalplanner-business/src/main/java/org/navalplanner/business/workreports/daos/WorkReportTypeDAO.java
index 100332613..44d82241b 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/workreports/daos/WorkReportTypeDAO.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/workreports/daos/WorkReportTypeDAO.java
@@ -72,7 +72,6 @@ public class WorkReportTypeDAO extends
             WorkReportType t = findUniqueByName(workReportType);
             return (t != null && t != workReportType);
         } catch (InstanceNotFoundException e) {
-            System.out.println("Intancia not found");
             return false;
         }
     }
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/workreports/entities/WorkReportType.java b/navalplanner-business/src/main/java/org/navalplanner/business/workreports/entities/WorkReportType.java
index c2dbc65d8..1355f6a8a 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/workreports/entities/WorkReportType.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/workreports/entities/WorkReportType.java
@@ -32,6 +32,7 @@ import org.hibernate.validator.Valid;
 import org.navalplanner.business.common.BaseEntity;
 import org.navalplanner.business.common.Registry;
 import org.navalplanner.business.common.exceptions.InstanceNotFoundException;
+import org.navalplanner.business.labels.entities.LabelType;
 import org.navalplanner.business.workreports.daos.IWorkReportTypeDAO;
 import org.navalplanner.business.workreports.valueobjects.DescriptionField;
 /**
@@ -224,6 +225,38 @@ public class WorkReportType extends BaseEntity {
         return true;
     }
 
+    @SuppressWarnings("unused")
+    @AssertTrue(message = "the assigned label type can not repeat in the work report type.")
+    public boolean validateNotExistRepeatedLabelTypes() {
+        for (WorkReportLabelTypeAssigment assignedLabelType : this.workReportLabelTypeAssigments) {
+            if (existRepeatedLabelType(assignedLabelType)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    public boolean existRepeatedLabelType(
+            WorkReportLabelTypeAssigment assignedLabelType) {
+        for (WorkReportLabelTypeAssigment oldAssignedLabelType : this.workReportLabelTypeAssigments) {
+            if ((!oldAssignedLabelType.equals(assignedLabelType))
+                    && (isTheSameLabelType(oldAssignedLabelType.getLabelType(),
+                            assignedLabelType.getLabelType()))) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public boolean isTheSameLabelType(LabelType oldLabelType,
+            LabelType newLabelType) {
+        if ((oldLabelType != null) && (newLabelType != null)
+                && (oldLabelType.equals(newLabelType))) {
+            return true;
+        }
+        return false;
+    }
+
     public boolean existSameFieldName(DescriptionField descriptionField) {
         for (DescriptionField oldDescriptionField : getDescriptionFields()) {
             if ((!oldDescriptionField.equals(descriptionField))
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/workreports/WorkReportModel.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/workreports/WorkReportModel.java
index c0c56e36e..c9f5360d4 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/workreports/WorkReportModel.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/workreports/WorkReportModel.java
@@ -383,8 +383,8 @@ public class WorkReportModel implements IWorkReportModel {
     }
 
     private DescriptionField getDescriptionFieldByName(String name){
-        WorkReportType type = getWorkReport().getWorkReportType();
-        for (DescriptionField descriptionField : type.getDescriptionFields()) {
+        for (DescriptionField descriptionField : getWorkReportType()
+                .getDescriptionFields()) {
             if(descriptionField.getFieldName().equals(name)){
                 return descriptionField;
             }
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/workreports/WorkReportTypeCRUDController.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/workreports/WorkReportTypeCRUDController.java
index 1a5dc5983..5cef1de7d 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/workreports/WorkReportTypeCRUDController.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/workreports/WorkReportTypeCRUDController.java
@@ -435,7 +435,6 @@ public class WorkReportTypeCRUDController extends GenericForwardComposer
             DescriptionField descriptionField) {
         PositionInWorkReportEnum newPosition = (PositionInWorkReportEnum) selectedItem
                 .getValue();
-        System.out.println("**" + newPosition.name());
         workReportTypeModel.changePositionDescriptionField(newPosition,
                 descriptionField);
     }
@@ -520,6 +519,8 @@ public class WorkReportTypeCRUDController extends GenericForwardComposer
             public void onEvent(Event event) throws Exception {
                 changeLabelType(comboLabelTypes.getSelectedItem(),
                         workReportLabelTypeAssigment);
+                validateIfExistTheSameLabelType(comboLabelTypes,
+                        workReportLabelTypeAssigment);
                 Util.reloadBindings(listWorkReportLabelTypeAssigments);
             }
         });
@@ -727,6 +728,17 @@ public class WorkReportTypeCRUDController extends GenericForwardComposer
         };
     }
 
+    public void validateIfExistTheSameLabelType(
+          final Combobox comboLabelTypes,
+          final WorkReportLabelTypeAssigment workReportLabelTypeAssigment) throws WrongValueException {
+        if ((getWorkReportType() != null) && (getWorkReportType().existRepeatedLabelType(workReportLabelTypeAssigment))) {
+                      workReportLabelTypeAssigment.setLabelType(null);
+                      throw new WrongValueException(
+                    comboLabelTypes,
+                    _("This label type already is assigned to the work report type."));
+        }
+    }
+
     public Constraint validateIfExistTheSameFieldName(
             final DescriptionField descriptionField) {
         return new Constraint() {
@@ -790,7 +802,7 @@ public class WorkReportTypeCRUDController extends GenericForwardComposer
                 .validateLabelTypes();
         if (labelTypeAssigment != null) {
             selectTab(tabReportStructure);
-            String errorMessage = "The label type must not null.";
+            String errorMessage = "The label type must unique and not null.";
             showInvalidWorkReportLabelTypeAssigment(0, errorMessage,
                     labelTypeAssigment);
             return false;
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/workreports/WorkReportTypeModel.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/workreports/WorkReportTypeModel.java
index 497230d96..047f9e0ae 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/workreports/WorkReportTypeModel.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/workreports/WorkReportTypeModel.java
@@ -408,7 +408,9 @@ public class WorkReportTypeModel implements IWorkReportTypeModel {
 
     public WorkReportLabelTypeAssigment validateLabelTypes() {
         for (WorkReportLabelTypeAssigment labelTypeAssigment : getWorkReportLabelTypeAssigments()) {
-            if (labelTypeAssigment.getLabelType() == null) {
+            if ((labelTypeAssigment.getLabelType() == null)
+                    || (getWorkReportType()
+                            .existRepeatedLabelType(labelTypeAssigment))) {
                 return labelTypeAssigment;
             }
         }