The use of obstetric analgesia was investigated in a Swedish population-based prospective study of 335,207 births, which represents almost all women who had vaginal deliveries in Sweden between 1983 and 1986. Lumbar epidural analgesia (EDA) was used in 16%, paracervical block (PCB) in 12%, pethidine or morphine in 49% and pudendal block in 62%. All four types of analgesia were much more commonly used by nulliparae than multiparae. Variables such as maternal age, smoking, nationality, relationship with the infant's father and gestational age had only moderate influence on the rates of different types of analgesia. EDA and PCB were more frequently used in larger than in smaller hospitals and in the daytime than at night. No such differences were found for pethidine or morphine, or pudendal block, which were administered routinely by midwives.