Introduction: Ulnar bone deficiency is one of rarest congenital anomalies of upper limb which is classified under longitudinal deficiencies of upper limb. Ulnar bone deficiency is classified to several subgroups and musculoskeletal deformities are very common in this abnormality. Hand always has abnormality in the involved limb. The presenting case has ulnar deficiency with humero-radial synostosis, but interestingly no abnormality in ipsilateral  hand and digits.

Case Report: The patient is an 8 year old boy who had referred to the clinic because of short left upper extremity. On examination of the spine, lower extremities and right upper extremity no abnormality was found. The involved left upper limb was shorter than the right upper limb, elbow was in extension and there was no motion at that joint. Left wrist was similar to the right one. In the left hand, thumb was normal and all metacarpal bones were normal. Hand had five digits with three phalanges without any syndactylism and constrictive bonds. On radiographic examination, there was humero - radial synostosis, but no abnormalities in the bones of hand.

Conclusion: Presenting report indicates the presence of ulnar bone deficiency without the abnormality of the hand in the involved limb.