We report a rare case of retinal detachment with microphthalmos and choroidal coloboma. A 28-year-old man who had suffered from poor vision since early childhood was examined because of progressive deterioration of vision in his right eye. Examination of the anterior segment showed microphthalmos with microcornea and coloboma of the iris. Fundus examination revealed an inferior choroidal coloboma extending to the optic disc. The patient also had total bullous retinal detachment. Pars plana vitrectomy with silicone oil tamponade was performed, and the retina was reattached. Although rare, retinal detachment may develop in patients with microphthalmos and choroidal coloboma. Pars plana vitrectomy with additional scleral encircling buckle may be performed to treat this condition.