A 2-year retrospective review of 238 cases of acute scrotal pain encountered in a children's hospital emergency department is presented. The incidences of testicular torsion, torsion of a testicular appendage, and epididymitis were 16%, 46%, and 35%, respectively. Testicular salvage was critically dependent on the interval between onset of pain and surgical intervention. No testis likely to have been viable at the time of presentation was "lost." The diagnostic error rate on first encounter was 7%, resulting in 10 negative scrotal explorations. With the exception of cases of far-advanced necrotic testes, both color Doppler ultrasound and radioisotope imaging were highly specific diagnostic modalities. Thirty-nine percent of the children with epididymitis who underwent investigation were found to have either structural or functional urinary tract abnormalities. Noninvasive urodynamic studies appear to be useful screening modalities in older children with epididymitis.