To define the ultrasound (US) prevalence of varicoceles after surgical repair, 28 postoperative patients underwent color Doppler US. A group of 26 control subjects also underwent color Doppler US to establish the prevalence of varicoceles in the healthy population. Eighteen of 28 (64%) patients who underwent color Doppler US scanning 16.4 months, on average, after varicocele repair had evidence of a varicocele, a number similar to that reported in other series for infertile men before surgery. Dominant veins in the postoperative patients were larger (P < .01) than those in the control subjects. Postoperative improvements in sperm parameters and conception rate in our subjects were 58% and 43%, respectively, consistent with findings reported in the literature. The prevalence of varicoceles detected at color Doppler US in our healthy population was 42% (11 of 26). Physical examination after surgery failed to show a varicocele in 20 of 22 (91%) patients examined. The discrepancy between sperm parameters and the results of color Doppler US and physical examination raises questions about the utility of US as a means of evaluation in the postvaricocelectomy patient.