Morphine at very low dose gives a good post-operatory analgesia without major secondary effects. This study analyses retrospectively 285 spinal anaesthesia with hyperbaric 0.5% bupivacaine 0.2 mg.kg-1 and morphine 0.25 mg in adult urologic surgery. The analysis of enquiry in analgesic during the post-operatory period shows that in most cases (72%) the patients have supported the first 24 hours without any complementary analgesia; 28% of patients needs a complementary analgesia realized with 1 g of paracetamol. Intravenous morphinics have never been necessary in post-operative period. The analgesia was adequate for the patient's comfort, and it never mask a surgery complication. No respiratory complication appeared, even in 13 patients who needed intravenous morphinics in per-operative.