Background: Intra‐anal injectable agents have been used to treat faecal incontinence. The aim of this study was to report the experience of a cohort of patients who underwent intra‐anal injection of collagen and to determine which patients benefited from the technique. Methods: Data, including age, sex, incontinence score, classification of incontinence, baseline resting pressure and vector volume, were collected prospectively for 73 consecutive patients (59 women) undergoing intra‐anal collagen injection. Patients were reviewed after treatment and incontinence scores documented. A proportion of patients also underwent repeat anorectal physiological testing 8 weeks after the procedure. Results: At a median follow‐up of 12 months after the intra‐anal injection, 63 per cent of patients had an improved incontinence score and 73 per cent reported an overall improvement in symptoms. Logistic regression showed that older age and idiopathic faecal incontinence were predictors of a successful outcome (P = 0·042 and P = 0·048 respectively). Conclusion: Intra‐anal collagen injection appears to have a role in the treatment of faecal incontinence. The majority of patients can expect both objective and subjective improvement. The best results are achieved in older patients and in those with idiopathic incontinence. Copyright © 2006 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. Best results in older patients