This study reports on 62 health care professionals referred to a specialist drug and alcohol treatment service. Most patients used more than one type of substance. Health problems were common, but were seldom reasons for referral. Self-referral was infrequent. Referral was often subsequent to intoxication at work or persistent absenteeism. Just over half of admissions completed treatment. Multiple drug use was a poor prognostic indicator with fewer multiple drug users engaging with, or completing, treatment.