S-(trans-1,2-Dichlorovinyl)-L-cysteine (DCVC) exposure causes acute renal tubular cytotoxicity. To further characterize the effects of DCVC, a chronic study was undertaken. Male Swiss-Webster mice received DCVC dissolved in their drinking water at 0.01, 0.05 and 0.1 mg ml-1. At 4, 8, 21 and 37 weeks, animals were terminated. Bladders, spleens, livers, kidneys and eyes were removed for histopathological examination. At 0.05 and 0.1 mg ml-1 DCVC, growth retardation was evident by 21 weeks. By 26 weeks, all animals in the 0.1 mg ml-1 group had developed cortical cataracts. Cytomegaly, nuclear hyperchromatism and multiple nucleoli were noted in the cells of the pars recta region of the kidney by 4 weeks and correlated to time and dose. At later time points, renal tubular atrophy and early interstitial fibrosis were evident. The epithelial cytological cellular abnormalities appear to be dose-related. Minor pathological changes were noted in the spleen, while there was no effect on the liver or bladder. Chronic ingestion of DCVC results in severe kidney injury.