No intervention has been shown to be effective in preventing repetition of self-harm. In the 6-month follow-up of a large randomised controlled trial, we previously reported no effectiveness of the provision of a card offering 24-h crisis telephone consultation on repetition of self-harm. However, there was a possible benefit among those presenting following a first episode (OR=0.64, 95% CI 0.34–1.22). Here we report the 12-month follow-up of the trial. The results confirm no overall benefit of the intervention (OR=1.19, 95% CI 0.85–1.67). Among those with a first episode of self-harm, the possible benefit of the intervention had diminished (OR=0.89, 95% CI 0.52–1.52), although a modest effect cannot be excluded.