The intraperitoneal instillation of 32% dextran 70 (HyskonR, Pharmacia AB, Sweden) has previously been reported to prevent the formation of postoperative adhesions. Against this background, the present study was undertaken to evaluate the efficacy of HyskonR in counteracting peritoneal adhesions following tubal microsurgery. 105 infertile women were operated upon in a prospective, randomized, controlled, double-blind, multicenter study. The intra-abdominal adhesions present from the beginning were classified by means of a standardized scoring scale and the extent of adhesions was again evaluated at follow-up laparoscopy 4-10 weeks later. A reduction in the extent of the intra-abdominal adhesions (statistically highly significant) was revealed in both the Hyskon group and the saline control group. The extent of adhesions in the Hyskon group was not lesser than in the saline group, however. The pregnancy rates in the two groups were also similar.