The study aimed to determine patterns of use of medical services and prescriptions for pharmaceuticals among 438 heroin users interviewed for the Australian Treatment Outcome Study (ATOS) at baseline, 12 and 24 months. Drug use declined markedly, and there were significant improvements in health. There were declines in the proportion of participants who had attended a general practitioner (GP) (baseline: 60%, 12 months: 53%, 24 months: 52%), who had an ambulance attendance (11%, 7%, 5%), and who were treated in an accident and emergency department (11%, 6%, 5%). While there was no decrease in the proportion who obtained a prescription (47%, 45%, 46%), there was a decrease in the mean number of reported prescriptions obtained (2.3, 1.0, 0.9). There were also differences across follow-up in the reported types of medications obtained, with a significant decrease in the proportion obtaining psychotropic medications (38%, 21%, 19%). In particular, there were large declines in the proportion who reported benzodiazepines (30%, 12%, 10%) or narcotic analgesics (8%, 3%, 4%) on prescription. While ATOS participants continued to be frequent users of health services, the cohort reported reduced levels of drug-seeking and risk commensurate with their reductions in drug use.