A young man's serious sexual misbehaviour, which resulted in his being banned from his ATC, was tackled using a behavioural approach (reinforcement of appropriate behaviours) and counselling. This combined programme had an immediate effect in reducing his overt sexual activities at the Centre and promoting his acceptability there which has been maintained in the succeeding three years. The token system used helped not only to structure the young man's response but also, as concrete evidence of his success, to change attitudes towards him of Centre staff.