The efficacy of various methods in preventing headache following spinal anesthesia was compared in 797 patients. The postspinal headache occurred in 17.8% of the patients in whom the lumbar puncture was done with a 22-gauge needle. The use of a 26-gauge needle reduced the occurrence of the headache to 7.8% (P < 0.0125) and the administration of 100 mg indomethacin 6 h after the blockade to 10.3% (P < 0.05) of the patients. The hydration, an infusion of 3000 ml fluids during the operation day as compared to that of 1500 ml, the recumbency of 24 h compared to that of 8-16 h, and prophylactic epidural blood patching did not prevent headache. Headache occurred more often in young patients and in patients who had a history of repeated headache or migraine. In patients with postspinal headache indomethacin relieved pain as effectively as a stronger analgesic-mixture. Other complaints occurring after the blockade were pain in the lower back in 9.7% and pain in the lower extremities in 7.2% of patients. The lithotomy position during the blockade predisposed the patients to these complications.