A single masked observer examined 55 non-diabetic patients chosen randomly from a population of patients who had undergone renal transplant. The mean age was 41 years and mean time from transplant was 4.4 years (1-10 years). Fourteen patients were found to have a posterior subcapsular cataract (PSC). The axial thickness of the right lens of the renal transplant population, even in the presence of a PSC, was significantly larger than in a control population of 99 patients with clear lenses. The PSC of renal transplantation is readily distinguished from age related PSC because the opacity lies in the superficial cortex at a depth proportional to time from transplant and the lens maintains a normal anterior clear zone. It is proposed that this type of cataract be called 'recovering' PSC. It is concluded that the cataractogenic insult occurs mainly during the peritransplant period. Maintenance doses of immunosuppressives or steroids are therefore probably not cataractogenic.