The therapy for diabetic macular oedema often remains unsatisfactory for both patient and treating physician. Therapeutic approaches comprise laser therapy as the evidence-based "basic therapy" and increasingly also intravitreal injections of drugs which, however, have only a limited effect. One argument for the use of vitrectomy in the treatment of diabetic macular oedema is its potentially permanent positive effect. On the one hand, removal of the adherent vitreous may facilitate the supply of the inner retina "per diffusionem" from the vitreous, on the other hand it may allow movement of harmful cytokines from the retina into the vitreous also by diffusion. Furthermore, from the pathophysiological standpoint, the vitreoretinal interface itself is modified by glycosylation processes and may thereby contribute to the occurrence of macular oedema. Pathological vitreofoveolar adhesions, which now can be visualised by use of ocular coherence tomography, may also add to the development of macular oedema in a mechanical-tractive manner. A critical analysis of the published clinical studies reveals that the macular retinal thickness is indeed reduced after vitrectomy, disappointingly however, this does not translate into better visual acuity in patients without detectable tractive components. But, in the case of eyes with tractive components of the diabetic macular oedema, there is good evidence for a surgical approach.