The efficacy of pneumatic compression of the lower limbs using inflatable leg splints in prevention of hypotension during spinal anaesthesia was assessed in an open study of 46 patients undergoing elective caesarean section. All patients received 15 ml/kg of Hartmann's solution before spinal anaesthesia and were tilted to the left to minimise aortocaval compression. Splints were rapidly inflated to a pressure of 5.3 kPa immediately after institution of the block in treated patients. Blood pressure was measured by a cuff method at 1-min intervals until the commencement of surgery. Hypotension was less common (P less than 0.05) and less severe (P less than 0.05) in splint-treated patients, but the incidence was unacceptably high in both treated (48%) and control (83%) groups.