Seventy-eight opiate abusers were followed up after successful in-patient detoxification in order to examine renewed opiate use. The greatest number of initial lapses occurred within a week of subjects leaving in-patient treatment. Eleven categories of lapse precipitant were identified: cognitive, mood, external, withdrawal, interpersonal, leaving a protected environment, drug availability, drug-related cues, craving, priming, and social pressure. Cognitions, negative moods and external events emerged as the most commonly mentioned factors; these often occurred together, either in clusters or in a sequence. Implications of these results for models of relapse and for treatment approaches are discussed.