['Using sonography, the bicornate and septate uterus as causes of failure of quinacrine sterilization (QS) are explored. Whether QS can be effectively performed on women with a bicornate or septate uterus is a question answered by a presentation of three such cases.', 'Three cases presented were part of a prospective nonrandomized study of QS in 205 women requesting sterilization at the Family Planning Clinic, School of Medicine of the Federal University of Minas Gerais, Belo Horizonte, Brazil. Sonography was performed on all patients before, during and after QS. Quinacrine was packaged as seven pellets in a modified Copper-T IUD inserter (Sipharm, Sisseln, Switzerland). Each woman received the first transcervical insertion of 252 mg of quinacrine during the follicular phase of the menstrual cycle, usually immediately after menses. One month later, a second insertion was similarly performed. Patients were advised to use an alternate method of birth control for 12 weeks to allow time for scarring of the oviducts. A blood pregnancy test was done before the QS procedure.', 'The diagnosis of a septate or bicornuate uterus was made by sonography in three of the 205 patients in the study. It was obvious that quinacrine had to be inserted into the two horns of such an anomalous uterus if the dissolved drug was to enter both fallopian tubes. Quinacrine dissolved into "lakes of quinacrine," and sonographically could be seen at the top of the uterine fundus. For this clinical trial of 205 patients, there were 546 woman-years of follow-up, and the Pearl index was 0.73 per 100 woman-years (95% confidence limits: 0.02, 1.4).'] Does sonographic recognition of three cases of septate uteri diminish failures of quinacrine sterilization?