A substantive amendment to this systematic review was last made on 19 May 1999. Cochrane reviews are regularly checked and updated if necessary. ABSTRACT Background and objectives: Approximately 70% of women will experience some degree of perineal trauma following vaginal delivery and will require stitches. This may result in perineal pain and superficial dyspareunia. The objective of this review was to assess the effects of absorbable synthetic suture material as compared with catgut on the amount of short- and long-term pain experienced by mothers following perineal repair. Search strategy: We searched the Cochrane Pregnancy and Childbirth Group trials register. Selection criteria: Randomised trials comparing absorbable synthetic (polyglycolic acid and polyglactin) with plain or chromic catgut suture for perineal repair in mothers after vaginal delivery. Data collection and analysis: Trial quality was assessed independently by two reviewers. Data were extracted by one reviewer and checked by the second reviewer. Main results: Eight trials were included. Compared with catgut, the polyglycolic acid and polyglactin groups were associated with less pain in first three days (odds ratio 0.62, 95% confidence interval 0.54–0.71). There was also less need for analgesia (odds ratio 0,63, 95% confidence interval 0.52–0.77) and less suture dehiscence (odds ratio 0.45, 95% confidence interval 0.29–0.70). There was no significant difference in long-term pain (odds ratio 0.81, 95% confidence interval 0.61–1.08). Removal of suture material was significantly more common in the polyglycolic acid and polyglactin groups (odds ratio 2.01, 95% confidence interval 1.56–2.58). There was no difference in the amount of dyspareunia experienced by women. Reviewers' conclusions: Absorbable synthetic suture material (in the form of polyglycolic acid and polyglactin sutures) for perineal repair following childbirth appears to decrease women's experience of short-term pain. The length of time taken for the synthetic material to be absorbed is of concern. A trial addressing the use of polyglactin has recently been completed and this has been included in this updated review. Citation: Kettle C, Johanson RB. Absorbable synthetic versus catgut suture material for perineal repair (Cochrane Review). In: The Cochrane Library, Issue 4, 1999, Oxford: Update Software. ••• The preceding report is an abstract of regularly updated, systematic reviews prepared and maintained by the Cochrane Collaboration. The full texts of the reviews are available in The Cochrane Library (ISSN 1464-780X). See http://www.update-software.com/cochrane.htmor contact Update Software, firstname.lastname@example.org, for information on subscribing to The Cochrane Library in your area. Update Software Ltd, Summertown Pavilion, Middle Way, Oxford OX2 7LG, United Kingdom (Tel.: +44 1865 513902; Fax: +44 1865 516918).