Cystourethroscopy is an uncomfortable and often painful investigation for children. It is distressing to the parents, and even when it is done on a day case basis it can cause considerable disruption to the family. It should therefore only be considered when it is felt that the examination will contribute to the management of the urinary problem in the child, and then only after routine assessment including physical examination, urine culture, renal function studies, excretion urography and, where indicated, micturating cystogram. In a study of 242 children who had cystourethroscopy, it was found to be of only limited value in children with enuresis, incontinence, haematuria, recurrent urinary infection and painful micturition. In some children it provided an opportunity for either indirect (from instrumentation) or formal urethral dilatation and this seemed to be associated with post-operative symptom relief in some children. Endoscopy appeared to be of most value in the management of vesicoureteric reflux, upper tract duplication and specific urethral abnormalities. In these situations the examination provided essential information which was helpful with further management of the children.