Aims. To investigate whether heroin addicts demonstrate shortened time horizons and decreased sensitivity to future consequences of their behavior compared to non-drug users . Design Setting and Participants. Thirty-four heroin addicts enrolled in a buprenorphine treatment clinic and 59 non-drug-using controls completed a personality questionnaire and two laboratory tasks . Measurements. The Stanford Time Perception Inventory (STPI) personality questionnaire assessed orientation to the future, and the Future Time Perspective (FTP) task elicited predictions of the timing and ordering of future events. The Bechara card task measured preferences for decks of cards that range in magnitude and probability of delayed and immediate rewards and punishers . Findings. Heroin addicts scored significantly lower than controls on the STPI scale indicative of future orientation. In the FTP, heroin addicts were less likely to predict events far into the future and less likely to systematically organize events in the future. In the card task, heroin addicts were less likely to win money than controls. They were more likely to play from a deck that contained greater immediate gains but that resulted in large, delayed punishers and overall net losses. They also made fewer selections from a deck that provided an overall net gain via relatively low immediate rewards and frequent small punishments . Conclusions. Shortened time horizons and decreased sensitivity to delayed consequences may explain drug abusers' persistent use of drugs, despite the long-term negative consequences associated with drug use.