Objectives. The aim of this study was to establish and evaluate a direct access service for laparoscopic sterilization. Methods. A pragmatic randomized controlled trial was carried out on a total of 232 women referred to Aberdeen Royal Infirmary for sterilization between 1 June 1996 and 31 March 1997, from 57 general practices around Aberdeen, Scotland, comprising 75 from general practices that had received criteria for direct access, and 157 from control practices. The main outcome measures were: patients' waiting times to appointments and operation, satisfaction, short-term regret, operative complications and costs; conjoint analysis of patient preferences; GPs' adherence to referral criteria; GP and gynaecologist satisfaction; and NHS costs. Results. Analysis was by intention to treat. There were no inappropriate direct referrals. Waiting time was lower in the intervention group, but there were more visits post-operatively to the GP. Patient and doctor satisfaction was equally high in both groups. There was no difference in operative complication rate, nor in total cost to patients or to the NHS. GPs and gynaecologists strongly supported direct access, but women preferred to meet both a gynaecologist and a GP before sterilization (routine referral). Other attributes of care important to patients included written information, although waiting time was not important. Of all women referred for sterilization during the study period, only 31% were suitable for direct referral. Conclusions. Patients preferred routine referral, and there were no differences in patient costs or satisfaction. There was, however, strong medical support for direct referral. Restrictive direct referral criteria may limit the uptake. These findings are important for future planning of direct referral services. Important methodological lessons were also learnt about the conduct of trials involving the primary-secondary care interface.