Predicting treatment outcome in nocturnal enuresis. A presenting sample of 127 consecutive referrals to a community based enuresis clinic were evaluated after treatment with baseline behavioural recording and the enuresis alarm. Almost one in five became dry after baseline recording only while 81 of 96 (84%) enuretics who used the alarm achieved the initial dryness criterion. Successful outcome was associated with the absence of adverse environmental factors and psychiatric disorders in the child. A logistic regression procedure enabled a risk score to be created so that successful outcome could be predicted. Psychiatric disorder in the child, family stress, and the degree of concern shown by the child emerged as the most important prognostic factors in the treatment of enuresis. The favourable success rates with baseline recording and the enuresis alarm confirm the role of conditioning treatment at the forefront of management of enuresis and the risk score allows outcome to be predicted for the first time. 