The incidence and duration of postoperative ptosis was investigated in 64 patients undergoing cataract surgery. Thirty-two patients had a 2-point periocular regional anaesthesia while 32 others were given general anaesthesia. The palpebral aperture and the levator muscle function were measured preoperatively and then on the 1st, 2nd, 4th and 7th postoperative days or as long as ptosis persisted. On the 1st postoperative day, about half of the patients in both groups demonstrated ptosis. On the 2nd day, ptosis was more common in the general anaesthesia group. The ptosis persisted 1 week postoperatively in 2 patients, both belonging to the general anaesthesia group. It is concluded that postoperative ptosis is common both after local and general anaesthesia. In most cases it is shortlasting and may be related to the volume or myotoxicity of a local anaesthetic drug. The use of a superior rectus muscle bridle suture and/or lid speculum may be important in provoking ptosis of longer duration.