This is a report of a rare case of post-traumatic leptomeningeal cyst in a 25 year old female, who receiveddepressed and compound fracture in the left fronto-temporal bone and linear fractures in the left temporal bonefollowing a traffic accident. Plain skull series obtained on 4 months after the trauma demonstrates aleptomeningeal cyst measuring 2.0x1.5x0.5cm in its dimension in the left fronto-temporal bone associated withlinear fractures. Etiology, pathogenesis, symptoms and signs, roentgenological findings, differential diagnosis,prognosis and treatment of leptomeningeal cyst are discussed with a review of the literature.