Inverse Duane's retraction syndrome is very uncommon. Congenital cases are even more unusual. A 6-year-old girl with convergent squint along with severe restriction on abduction is described. On attempted abduction, a narrowing of the palpebral fissure, upshoot and retraction of the eyeball were observed. Brain and orbit MRI demonstrated no intracranial or intraorbital mass, fracture, or entrapment of the medial rectus. Forced duction test was strongly positive. The primary lesion was found to be a tight medial rectus with shortening and soft tissue contracture. Surgical tenotomy of the medial rectus led to successful postoperative motility, but some limitation at full adduction and abduction persisted. This is a case reported with congenital medial rectus shortening, suggesting that this condition may be one of the etiologies of the rare inverse Duane's retraction syndrome.