In comparison to conventional operating technique endoscopic surgery reveals numerous advantages, particular rapid mobilisation and earlier discharge from observation. For a effective utilization of these advantages, it is desirable to have a efficient postoperative analgesic scheme, which can be continued into the period after discharge from hospital. In a randomised, prospective double-blind study we investigated the analgesic efficacy of dipyrone in 40 patients, scheduled for endoscopic abdominal surgery (mainly endoscopic cholecystectomy). Patients received before induction of anesthesia either dipyrone (1 g/100 ml NaCl i.v.) or placebo (100 ml NaCl i.v.). These infusions were repeated 6 h and 12 h after first application. After surgery all patients were allowed to self-administer buprenorphine intravenously from a PCA-pump (Bolus 30 micrograms, lockout 5 min in the recovery room, 30 min on the ward). Every hour for the first 6 h and after 24 h, cumulated doses of buprenorphine, pain scores (0-10), pulse, blood pressure and side effects were recorded. Dipyrone-treated patients had significantly less pain immediately after surgery and used a significantly lower cumulated dose of buprenorphine (-67%; 90 micrograms vs. 270 micrograms buprenorphine) in the first 24 h after surgery.