Diabetic tractional retinal detachment is a severe complication in diabetic retinopathy. The decision for a surgical intervention has to consider the spontaneous course of the disease, intraoperative and postoperative complications and the expected functional results. An extramacular tractional detachment can remain stable for a long time and can be observed as long as the centre of the macula is not threatened. Traction to the macula can cause oedema and reduced vision, even if the macula itself is not detached. In these cases vitreous surgery can improve vision. Retinal breaks due to tractional membranes can cause a traction-rhegmatogenous retinal detachment which is usually rapidly progressive and requires early surgery. For cases with tractional detachment of the macula there is no alternative to surgery. In cases with long-standing and complete tractional detachment with severe retinal ischaemia the functional prognosis even after anatomically successful surgery is poor and it may be better not to operate.