Hirayama‘s disease is a rare benign disorder, also referred to as monomelic amyotrophy (MMA), Juvenile non progressive amyotrophy, Sobue disease. It is usually seen during periods of rapid growth (15–25 years). It is a focal, lower motor neuron type of disease. Distal upper extremities characteristically show weakness and atrophy. Hirayama disease manifests itself as a self–limited, asymmetrical, slowly progressive atrophic weakness of the forearms and hands predominantly in young males. The forward displacement of the posterior dura of the lower cervical dural canal during neck flexion has been postulated to lead to lower cervical cord atrophy with asymmetric flattening. In this paper a case is presented of this rare self–limiting disease. A 26–year old male patient presented with complaints of weakness of left little finger, insidious in onset, gradually progressive involving the other fingers of left hand followed by weakness of right upper limbs for 6 months. He also complaints of loss of muscle mass in left upper limb. MRI revealed the cardinal features of Hirayama disease. This case report presents information about the differential diagnosis, detailed symptoms and treatment methods of a Hirayama patient.