The mechanism of recanalization after resection of a segment of the fallopian tube by the Pomeroy sterilization method is discussed. At the level of resection, the epithelial lining of the fallopian tube tends to regenerate, covering the split ends and planes of cleavage of the resected surfaces and forming slitlike spaces and blind pouches lined by tall columnar cells. Scarring and subsequent retraction of both severed ends of the tubes tend to result in approximation; in some cases, the resected ends and the epithelial lining bridge the gap between the lumina, re-establishing patency of the tube. Surgical procedures that prevent approximation of the resected ends of the fallopian tubes or methods that seal the lumina should produce failure rates lower than those obtained with the classic Pomeroy sterilization method.