We treated 16 eyes with diabetic tractional retinal detachment with a new method of surgical dissection whereby diabetic preretinal membranes and adherent posterior hyaloid were excised and removed as a single unit. This method differs from previously reported methods of diabetic membrane dissection by utilizing the posterior hyaloid to lift and immobilize the membrane as the membrane is excised with horizontally cutting scissors. The preservation of the posterior hyaloid facilitates the separation of the membrane from the retina. Fibrovascular proliferation was more completely removed and bleeding was less than with membrane sectioning techniques. The major surgical complication was posterior retinal break (seven eyes), but with near complete relief of traction all breaks were successfully treated with gas tamponade and laser photocoagulation. Thirteen retinas were completely reattached with a minimum follow-up of four months. One eye developed an extramacular tractional retinal detachment, and two eyes developed peripheral (retrolenticular) fibrovascular proliferation. Eleven eyes had 5/200 or better visual acuity.