Voiding abnormalities are encountered frequently in pediatric patients. Symptoms of daytime incontinence, frequency and nocturnal enuresis in any combination may indicate underlying neurophysiologic detrusor imbalance. Incomplete evaluation of these symptoms can result in inappropriate medical therapy or even ineffective operations. Within the preceding 7 months 34 children with hard-core voiding abnormalities were evaluated with urodynamic techniques. Several categories of abnormal voiding patterns were identified, including the hyperactive external sphincter, uninhibited pediatric neurogenic bladder, detrusor hyperreflexia secondary to chronic cystitis, hyperactive external sphincter with hypotonic bladder and the hyperactive external sphincter with detrusor irritability. All patients received specific pharmacotherapy based on presenting signs and symptoms, and voiding pattern abnormality. Of the 24 patients who have been treated in this manner and were evaluated 83.5% have had complete remission of symptoms while on therapy, the remainder being improved but still having occasional symptoms. The technique and data demonstrate that children with hard-core voiding abnormalities can achieve rehabilitation with urodynamic assessment.