To report the spontaneous remodelling of retinal veins inadvertently severed during vitreous surgery. Four diabetic patients who underwent vitrectomy during which retinal veins were damaged were followed for at least 6 months. Haemorrhages from severed veins were controlled by raising intraocular pressure and by endodiathermy of the distal ends of the veins. This was followed by fluid/gas exchange. Remodelling of venous channels in the damaged areas was observed in all eyes. In three of the four eyes we found evidence of collateral veins. In the other eye we noted the connection of two ends of an interrupted vein. No signs of retinal vein occlusion (e.g. superficial retinal haemorrhages and retinal oedema) were observed. These findings suggest that a spontaneous remodelling mechanism to repair damaged venous channels may exist in retina.