Using image-directed and color Doppler ultrasonography (ICDUS), we examined 65 patients with single kidney biopsy and diagnosed one arteriovenous fistula (AVF) in each of 8 kidneys. Three of them were associated with pseudoaneurysms. Three of the patients with AVF who presented with macrohematuria underwent angiography. Therapeutic percutaneous embolization was performed in 2 of them. The remaining 6 patients were followed up with ICDUS. All the lesions had disappeared at the end of a 6-month period. We conclude that ICDUS is an easy and noninvasive imaging technique in the diagnosis of postbiopsy native renal AVFs.