A case of unilateral disc-shaped cataract with coloboma of the lens is reported. The patient, a 17-year-old girl, had best corrected visual acuity of 0.01 (+ 9 D) in the right eye and 1.2 in the left eye. Exotropia of 10 Hirschberg degrees was found in her right eye. The visual disturbance of that eye was thought to be due to amblyopia. The pupillary center of the lens was very thin and membranous, with no nucleus. A ring-like hypertrophic cataract was observed from the lens equator to the periphery of the pupillary area. A bow-shaped coloboma of the lens was found from 3 to 5 o'clock, where the Zinn's zonule was coarse. Some dozen bright white spots were dispersed temporally from the periphery of the macular ring. This combination of disc-shaped cataract with the coloboma of lens is the first such case reported.