To determine whether infants with isolated minor anomalies of the external ear are at increased risk of renal malformations.Consecutive infants with isolated minor anomalies of the external ear (preauricular skin tags, preauricular sinuses, ear pits, and misshapen pinnae) were offered renal ultrasonography by experienced sonographers over a 41 month period. The prevalence of renal anomalies in such infants was compared with that detected on routine fetal scanning during the same period.Ninety six of 13 136 liveborn infants (7.3/1000, 95% confidence interval (CI) 5.9 to 8.9) were noted to have isolated minor ear anomalies on routine neonatal examination, with preauricular skin tags being the most common (85%). Ninety one (95%) infants underwent renal sonography at a mean (SD) age of 40 (19.6) days. Only one infant (1.1%, 95% CI 0.03 to 5.9) had transient unilateral pyelectasia. During the same period, non-syndromic renal anomalies were found in 0.64% (95% CI 0.52 to 0.73) of infants, a prevalence no different from that of infants with minor ear anomalies (p = 0.44).Routine renal imaging is not warranted in infants with such minor external ear anomalies unless accompanied by other systemic malformations.