diff --git a/tensorflow_privacy/privacy/membership_inference_attack/data_structures.py b/tensorflow_privacy/privacy/membership_inference_attack/data_structures.py
index efabdd8..c992dc8 100644
--- a/tensorflow_privacy/privacy/membership_inference_attack/data_structures.py
+++ b/tensorflow_privacy/privacy/membership_inference_attack/data_structures.py
@@ -105,6 +105,25 @@ def _is_integer_type_array(a):
   return np.issubdtype(a.dtype, np.integer)
 
 
+def _is_last_dim_equal(arr1, arr1_name, arr2, arr2_name):
+  """Checks whether the last dimension of the arrays is the same."""
+  if arr1 is not None and arr2 is not None and arr1.shape[-1] != arr2.shape[-1]:
+    raise ValueError('%s and %s should have the same number of features.' %
+                     (arr1_name, arr2_name))
+
+
+def _is_array_one_dimensional(arr, arr_name):
+  """Checks whether the array is one dimensional."""
+  if arr is not None and len(arr.shape) != 1:
+    raise ValueError('%s should be a one dimensional numpy array.' % arr_name)
+
+
+def _is_np_array(arr, arr_name):
+  """Checks whether array is a numpy array."""
+  if arr is not None and not isinstance(arr, np.ndarray):
+    raise ValueError('%s should be a numpy array.' % arr_name)
+
+
 @dataclass
 class AttackInputData:
   """Input data for running an attack.
@@ -187,7 +206,19 @@ class AttackInputData:
         self.labels_test):
       raise ValueError('labels_test elements should have integer type')
 
-    # TODO(b/161366709): Add checks for equal sizes
+    _is_np_array(self.logits_train, 'logits_train')
+    _is_np_array(self.logits_test, 'logits_test')
+    _is_np_array(self.labels_train, 'labels_train')
+    _is_np_array(self.labels_test, 'labels_test')
+    _is_np_array(self.loss_train, 'loss_train')
+    _is_np_array(self.loss_test, 'loss_test')
+
+    _is_last_dim_equal(self.logits_train, 'logits_train', self.logits_test,
+                       'logits_test')
+    _is_array_one_dimensional(self.loss_train, 'loss_train')
+    _is_array_one_dimensional(self.loss_test, 'loss_test')
+    _is_array_one_dimensional(self.labels_train, 'labels_train')
+    _is_array_one_dimensional(self.labels_test, 'labels_test')
 
 
 @dataclass