Ulnar neuropathy at the elbow (UNE) may seem easy to diagnose when the characteristic clinical manifestations are present, and electrodiagnostic studies have high sensitivity, although they are non-localizing in some cases and unable to reveal structural lesions. Ultrasonography is noninvasive and able to find the exact location of the lesion and visualize perineural structures. We present two cases of UNE in which we found hypoechoic mass lesions near medial epicondyle with ultrasonography and discuss its usefulness in diagnosis of UNE.