We have a limited knowledge of the incidence, natural history and complications of aneurysms of the segmental branches of renal arteries. Two young female patients with intimal fibrodysplasia and aneurysms of the segmental branches of renal arteries are described. The presenting features were hypertension and hematuria. The diagnosis was achieved through an arteriogram. Both patients underwent aneurysmorrhaphy and one of them nephrectomy of a non-functioning kidney. Pathological examination revealed intimal fibrodysplasia; one of the specimens showed areas of calcification. The immediate postoperative period was uneventful. However, one of the patients died from cerebral haemorrhage 18 months from the operation. The other patient has remained asymptomatic 3 years postoperatively. The epidemiological aspects, risk factors and treatment are discussed.