We report two cases of cirsoid-type renal arteriovenous fistula (RAVF) which were difficult to differentiate from renal pelvic tumor by intravenous pyelogram (IVP) and computed tomography (CT) scan. Two women visited our department complaining of sudden asymptomatic macroscopic hematuria. CT scans showed an irregular mass in the right kidney. Magnetic resonance angiography (MRA) revealed a cirsoid-type RAVF. These patients were treated with transarterial embolization (TAE) using ethanol, geratin sponge, and a coil. It is suggested that MRA is useful for the diagnosis of renal arteriovenous fistula.