PIP: In southwest China between April, 1988, and March, 1990, providers at 5 family planning centers in Sichuan, Guangxi, Yunnan, and Guizhou provinces performed 2713 vasectomies using 7 occlusion techniques. They all used the no-scalpel vasectomy technique to expose, isolate, and divide the vas deferens. Researchers compared the follow-up outcomes of the various techniques during 1988 and 1992. The techniques included open-ended technique with the fascia interposition (group A); removal of vas segment and ends ligated with no. 1 silk suture (group B); vasectomy with fascia interposition on testicular ends (group C); same as group B plus cautery and washing the ends with phenol or 95% ethanol and normal saline (group D); folding and ligating prostatic ends with no. 1 silk suture (group E); electrocoagulation on ends of vas (group F), and open-ended without fascial interposition (group G). In the 2 years postvasectomy, 61 wives (2.57%) had at least 1 pregnancy. Sperm were still present in the semen of 27 of their vasectomized husbands at 2 years postvasectomy. Recanalization had occurred in 78 (3.29%) men overall. Among the 78 recanalization cases, 27 wives (34.6%) became pregnant (1.14% for the entire population). Group D cases whose vas ends were washed with phenol had a significantly higher reappearance rate of sperm than did those whose ends were washed with 95% ethanol (5.88% vs. 0; p .01). A significant difference in the reappearance rates of sperm in various technique groups occurred with group A having the lowest rate and group G having the highest rate (0.55% vs. 7.53%; p .0001). The reappearance rates for the 2 interposition groups were not statistically different (0.55% for group A and 2.63% for group C). Differences in the complication rates occurred (e.g., 0 for group A vs. 2.17% for group G; p .01). Based on these results, vasectomy plus interposition is the best vas occlusion technique.