A 19-year-old female patient with renovascular hypertension accompanied by focal segmental glomerulosclerosis like lesion in the contralateral kidney is described. She was admitted to our hospital for uncontrollable hypertension which was first pointed out at check-up when she was 18 years old. On admission physical examination revealed remarkable hypertension and a bruit around the umbilical region. Laboratory findings disclosed renal dysfunction and slight proteinuria (0.8-1.1 g/day). Arteriography revealed severe narrowing of the right renal artery suggesting fibromuscular dysplasia. Taken together, renovascular hypertension was diagnosed. She underwent an operation to reconstruct the artery with autotransplantation of the ipsilateral kidney in the pelvic cavity, and sections were taken from both kidney for histological evaluation during the procedure. After the operation her blood pressure normalized and proteinuria decreased. And interestingly, the kidney specimens revealed that the left side consisted of focal segmental glomerulosclerosis like lesion whereas the right was only of ischemic change. Hyperfiltration theory has recently been highlighted experimentally. And the etiology of the renal findings in this case may be based on such hemodynamic alteration as has been described in animal models. We present the case so that it may be of some help to understand how focal segmental glomerulosclerosis is brought about in humans.