Objective: Bladder scans are used extensively in adult urology to estimate urinary volumes. For children, smaller devices have been developed. Scarce literature shows conflicting results regarding the accuracy of measurements in children. The BladderScan® BVI 6200 has been developed to overcome some of the inaccuracies. We tested this device to see whether it can replace conventional ultrasound in a bladder retraining program. Patients and methods: 84 children (mean age 7.8 years) were included. Measurements with the BVI 6200 were compared to measurements with a graduated cylinder or with conventional ultrasound before and after micturition. All volumes were expressed in milliliters. The measured volumes were compared to each other in a Bland-Altman analysis. Results: Mean (bias) of the different measurements fell within 10% difference of measurements. The spread of the different measurements around the mean was however very large, with a broad spread of over- and under-estimations of different measured volumes. Conclusion: The BVI 6200 is not reliable enough to replace conventional ultrasound for measurements of bladder volumes. It is not advisable to use it in a bladder retraining program. © 2012 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.