The incidence of bilateral retinal detachment ranges from 12 to 15%. A retrospective study including of 141 patients with a systematical prophylactic treatment of the fellow eye is reported. After the prophylactic photocoagulation no bilateral retinal detachment occurred, no complication arose. The average follow-up was about 18 months. The authors describe the technique of the prophylactic argon laser treatment. This photocoagulation associates a focal treatment excluding suspicious lesions, and a 360 degree equatorial treatment, completed by several anterior radial rows and by a scattered but tight photocoagulation from the equator to the ora. The authors conclude that prophylactic and systematical treatment is safe and effective, avoiding the focal retinal detachments, anterior giant tears and probably many breaks. The follow-up is still too short to know the longterm percentage of bilateral detachments with such a treatment of the fellow eyes.