The relative infrequency of aneurysms of the branches of the renal artery produces some indecision as to the surgeon's therapeutical choice. The purpose of this study is to carefully examine the indications for surgical treatment and to select precise therapeutical criteria on the basis of 8 patients in whom aneurysms of the main renal artery or of its branches were diagnosed from 1978 to 1986. In 1 patient, the disease was bilateral with a ruptured main artery aneurysm. 5 aneurysms were treated surgically (the ruptured one by nephrectomy, 2 by ex situ revascularization and 2 by in situ revascularization). In the remaining cases, only periodical controls were performed. In 4 surgically treated patients, angiographic follow-up demonstrated a regular renal revascularization and in 1 patient a thrombosis on the site of the anastomosis. On the basis of personal experience, surgical treatment is required for aneurysms larger than 1.5 cm in size without or with partial calcification, aneurysms occurring in pregnant women or in patients likely to conceive in the future, expanding aneurysms, and renin-mediated hypertension. The introduction of microsurgical techniques and renal preservation makes it possible for the urologist to chose between various therapeutical means for the treatment of intrarenal aneurysms. Reconstruction of anatomical continuity of the arterial supply avoiding unnecessary operative demolishment is feasible.