Introduction and Aims. The aim of this study was to examine heroin careers among former users to assess desistance factors and explanations for sustained abstinence. Design and Methods. The study surveyed 107 former problematic heroin users who have achieved long-term abstinence about their experiences of achieving and sustaining abstinence. The cohort was recruited opportunistically from three sources, drawing heavily on former users working in the addictions field. Results. On average, the group had heroin careers lasting for just under 10 years, punctuated by an average of 2.6 treatment episodes and 3.1 periods of abstinence, and had been heroin abstinent for an average of 10 years at the time of completing the survey. The most commonly expressed reason for finally achieving abstinence was ‘tired of the lifestyle followed by reasons relating to psychological health. In contrast, when asked to explain how abstinence was sustained, clients quoted both social network factors (moving away from drug-using friends and support from non-using friends) and practical factors (accommodation and employment) as well as religious or spiritual factors. Treatment was not mentioned widely either in achieving or sustaining abstinence, in contrast to 12-Step, which was endorsed widely. Discussion and Conclusions. The study supports a careers perspective for examining heroin careers and indicates that, while achieving abstinence is possible for chronic opiate users, the path to sustained abstinence is complex and often reliant upon external support systems.