The materials and methods of placing tubal rings are now well known and have changed little since the initial description. Most applicators can be loaded with 2 rings, simplifying the operating procedure. The choice of rings should be carefully made since differences in quality have been found. The ring should be placed in the middle of the isthmus 3 cm from the uterine cornu. After placement, the tubal loop will disappear more or less rapidley. The menstrual cycle does not appear to be modified. Numberous studies have confirmed the efficacy of tubal occlusion with Yoon silicone rings. The failure rate varied from 0-6/1000 in the initial series of 2421 cases, some of which had a follow-up of 5 years. Most failures occur in the 1st 2 years. Among advantages of sterilization with Yoon rings are its great simplicity for well trained practitioners and rarity of complications if contraindications are respected; the simplicity of the required materials; the method's efficacy and possibly reduced rate of ectopic pregnancy compared to tubal electrocoagulation; the high rates of client satisfaction; and its high reversibility if microsurgical techniques are used. The main operating problem is the impossibility of use in case of tubal pathology or large tubal diameter. Tubal tearing represents the principal complication, with hemorrhage occasionally occurring; these complications are often the result of rough handling, failure to respect local contraindications, or operator inexperience. Placement of a ring on each tubal extremity in case of a complete rupture resolves the complication readily, but bipolar coagulation, thermocoagulation, or application of clips may also be done. Resort to laparotomy does not appear necessary for a skilled laparoscopist. In Yoon's inital series the rates of tearing and bleeding were respectively 3.3 and .7%. Pelvic pain may occur during the placement of rings when general anesthesia is not used.