The bladder hamartoma is an extremely rare entity. We report on its presence in a 5-year-old boy with Goldenhar syndrome. Most probably, this is the first report of a bladder hamartoma presenting with obstruction of the bladder outlet resulting in urinary retention. The obstructive lesion was resected endoscopically. This proved to be curative for the lesion, since the follow-up voiding cysto-u...