To perform ambulatorial surgery with local anaesthetics, it is important to carry out a correct postsurgical NSAID therapy avoiding the risks induced by these drugs. Two groups of patients submitted to ambulatorial hemorrhoidectomy were enrolled in a randomized study to evaluate the safety of NSAID therapy with or without the coadministration of misoprostol, a PGE1 analogue with gastroprotective action. Aim of this study was to evaluate if misoprostol in coadministration with NSAID could permit a correct domiciliary postsurgical NSAID therapy without gastric symptoms related to the NSAID therapy. From January 1990 to December 1991, 95 patients underwent hemorrhoidectomy and were discharged with analgesic therapy: the first group (n = 45) without gastroprotective therapy, the second group (n = 50) with the coadministration of misoprostol 200 mcg bid. After 7 and 14 days of treatment patients showed the following symptoms: in the first group 13.3% of the cases showed mild epigastric pain, 8.8% moderate epigastric pain and 4.4% severe epigastric pain with heartburn; in the second group (NSAID + misoprostol) only 4% of the cases showed moderate epigastric pain. The incidence of epigastric pain was statistically higher (p < 0.05) in patients treated with NSAID alone in comparison with the group treated with NSAID + misoprostol. The results, according to international literature, show that correct gastro-protective therapy with synthetic prostaglandins (misoprostol) is necessary for patients in treatment with NSAIDs.