Retinal detachment associated with congenital coloboma of choroid is an unusual type of the disease 32 cases (34 eyes), or 1.23% of all 2,602 cases of retinal detachment, were operated on during 1980 to 1986. 17 (53%) patients were under 20 years of age and 28(88%) under 30 years. Preoperative visual acuities ranged from light perception to 0.2, and 25 eyes(74%) under 0.05. The associated congenital abnormalities were coloboma of iris in 32 eyes(94%), cataract in 25(74%), microcornea in 17(50%), and nystagmus in 13(38%). The detection of breaks in the rudimentary retina was extremely difficult, with a positive rate of only 56%, and immediate operative success was obtained in 18 eyes(53%), which were followed up for an average 36 months with re-detachment in 5 eyes. The rate of long term operative success was 38%. With the choroidal coloboma below the optic disc, the retinal breaks outside of the coloboma or in the coloboma near the edge, or the detachment involving at most 3 quadrants of the fundus, the rates of operative success were 81%, 70%, and 100% respectively.