It is well known that tardy ulnar nerve palsy occurs with cubitus valgus deformity as a late complication after a nonunion of lateral condyle fracture of the humerus in childhood. On the other hand, cubitus varus deformity often results from malunion of supracondylar fractures of the humerus. However, reports of tardy ulnar nerve palsy in cubitus varus deformity are few. We report a patient with bilateral cubitus varus deformities with bilateral tardy ulnar nerve palsy which was confirmed with EMG. She was treated by step cut osteotomy(DeRosa and Graziano) with sub­cutaneous anterior transposition of ulnar nerve