Purpose We assessed urinary flow patterns in newborn males using ultrasound flow probes. Materials and Methods Specifically customized ultrasound flow probes connected to a flowmeter were mounted on the penis of 30 newborn males. Flow data together with signals from a silent diaper alarm were sampled to a personal computer, and the flow curves were assessed with regard to configuration, maximum flow rate and voided volume. Studies were performed under the surveillance of a nurse, who together with the parents registered episodes of breast-feeding and periods of sleep and arousal, which were rated on a visual analogue scale and converted to percentages with 0% representing quiet sleep and 100% representing the fully awake state. Data were analyzed using the Kruskal-Wallis test and are presented as median (range). A p value of less than 0.05 was considered significant. Results The data from 23 neonates were applicable for analysis, and a total of 61 flow assessments were completed. Configuration was bell-shaped in 57% of the studies, interrupted in 18%, staccato in 8%, plateau in 5%, tower flow in 3% and “spike-dome” in 8%. Median voided volume was 10.6 ml (range 1.4 to 65.0) and median maximum flow rate was 2.3 ml per second (0.5 to 11.9). During all but 3 voids the neonates exhibited some degree of arousal. We found no significant correlation between curve configuration and voided volume, maximum flow rate or state of arousal. Conclusions Urinary flow curves in newborn males consisted of a known repertoire of configurations, in addition to a “spike-dome” shape not previously described. Of the assessments 34% were dyscoordinated. Voiding tended to occur in the awake state.