diff -u b/field_collection.entity.inc b/field_collection.entity.inc
--- b/field_collection.entity.inc
+++ b/field_collection.entity.inc
@@ -337,6 +337,22 @@
           }
         }
       }
+      // If we don't find the delta in the current values (cause the item
+      // is being deleted, for example), we search the delta in the originalcontent.
+      if (!empty($entity->original)) {
+        foreach ($entity->original->{$this->field_name} as $langcode => &$data) {
+          foreach ($data as $delta => $item) {
+            if (isset($item['value']) && $item['value'] == $this->item_id) {
+              $this->langcode = $langcode;
+              return $delta;
+            }
+            elseif (isset($item['entity']) && $item['entity'] === $this) {
+              $this->langcode = $langcode;
+              return $delta;
+            }
+          }
+        }
+      }
     }
   }