<i>Aim:</i> To determine the prevalence of renal anomalies in patients with an isolated single umbilical artery (SUA). <i>Methods:</i> We performed a retrospective study of all renal ultrasound examinations assessed at our centre between January 1998 and December 2008 in neonates with SUA with or without associated anomalies. <i>Results:</i> Renal ultrasound examination was performed in 65 neonates with SUA (57 neonates with isolated SUA and 8 neonates with nonisolated SUA). The prevalence of renal anomalies in the group with and without isolated SUA was 2% (1/57) and 38% (3/8), respectively. Only one patient with isolated SUA had a mild renal abnormality without clinical consequences. <i>Conclusions:</i> The prevalence of renal anomalies in neonates with isolated SUA is low. We suggest that routine ultrasound screening for renal anomalies is not warranted in neonates with isolated SUA.