Background: Benzodiazepine withdrawal programmes have never been experimentally compared with a non-intervention control condition. Aims: To evaluate the efficacy and feasibility of tapering off long-term benzodiazepine use in general practice, and to evaluate the value of additional group cognitive-behavioural therapy (CBT). Method: A 3-month randomised, controlled trial was conducted in which 180 people attempting to discontinue long-term benzodiazepine use were assigned to tapering off plus group CBT, tapering off alone or usual care. Results: Tapering off led to a significantly higher proportion of successful discontinuations than usual care (62% v. 21%). Adding group CBT did not increase the success rate (58% v. 62%). Neither successful discontinuation nor intervention type affected psychological functioning. Both tapering strategies showed good feasibility in general practice. Conclusions: Tapering off is a feasible and effective way of discontinuing long-term benzodiazepine use in general practice. The addition of group CBT is of limited value. Declaration of interest: None. The study was funded by the Dutch Health Care Insurance Council.