OBJECTIVE: To evaluate the effectiveness of standard regimes (ice packs and Epifoam) at relieving perineal trauma and compare these with a new cooling device (maternity gel pad). DESIGN: A randomised controlled trial involving three treatment groups. The women were free to choose the time of initial application (within four hours after delivery) in all treatment groups and the number of subsequent treatments up to 48 hours after suturing. SETTING: A midwifery unit in the north of England and then continued in the women's own homes. PARTICIPANTS: 120 women who had undergone an instrumental delivery and had a 48 hours post-delivery stay in a postnatal ward. MEASUREMENTS AND FINDINGS: The ordinal scale of none, mild, moderate and severe was used to determine the levels of perineal oedema and bruising at initial assessment (less than 4 hours), 24 hours and at 48 hours, by use of a newly developed visual evaluating tool. Self-assessed pain was recorded using a 10-point visual analogue scale within four hours, at 24 hours, 48 hours, and finally at five days after suturing. Women's opinions as to the effectiveness of their treatment was rated by use of a 5-point scale describing the categories; poor, fair, good, very good and excellent. A high proportion of women had some perineal oedema at initial assessment. A statistically significant difference in the proportion of women with oedema was found between treatment groups at 48 hours (p = 0.01), which was in favour of the maternity gel pad group. This was particularly noticeable for women with initial levels of mild oedema (p = 0.017). Localised treatment with the gel pad caused a significant decrease in reported pain at 48 hours in women who initially demonstrated moderate or severe pain (p = 0.048). A significant increase in the proportion of women with some bruising was seen across all treatment groups from initial assessment, through 24 hours to 48 hours (p < 0.0005). The bruising was significantly less in the gel-pad group in women who initially had no bruising (p = 0.021). There was no statistically significant effect of treatment at other initial levels of severity for oedema, bruising or pain at 24 hours, 48 hours and five days (for pain). Women in the gel-pad group rated the effectiveness of their localised treatment to be significantly higher than women in the other two treatment groups (p < 0.0005). KEY CONCLUSIONS: This trial demonstrated that a high proportion of women experience perineal oedema, bruising and pain following an instrumental delivery, which continues for at least five days for perineal pain, despite oral analgesia. Maternity gel pads, which were specially designed to cool the perineal region, were more effective in alleviating perineal trauma when compared with hospital standard regimens and were more highly rated by women.