diff --git a/flask_admin/model/fields.py b/flask_admin/model/fields.py
index ed28c7e88..d49841c94 100644
--- a/flask_admin/model/fields.py
+++ b/flask_admin/model/fields.py
@@ -119,11 +119,20 @@ def __init__(self, form_class, pk, form_opts=None, **kwargs):
         self.form_opts = form_opts
 
     def get_pk(self):
+        """Get the primary key value from the form"""
+        try:
+            if isinstance(self._pk, (tuple, list)):
+                return tuple(getattr(self.form, pk).data for pk in self._pk)
+
+            return getattr(self.form, self._pk).data
+        except AttributeError:
+            if self._pk not in self.form:
+                raise AttributeError(
+                    'Primary key field "%s" is required in inline_models "form_columns". Available form fields: %s'
+                    % (self._pk, self.form._fields.keys())
+                )
+            raise
 
-        if isinstance(self._pk, (tuple, list)):
-            return tuple(getattr(self.form, pk).data for pk in self._pk)
-
-        return getattr(self.form, self._pk).data
 
     def populate_obj(self, obj, name):
         for name, field in iteritems(self.form._fields):