A remotely controllable gastric banding device (10) for placement around the stomach of a patient for the treatment of obesity. The device (10) comprises a gastric band (10) having an inflatable chamber (16) for adjusting the inner circumference of the band (10), a pressurized reservoir (20) with a valve (31) for providing fluid to inflate the inflation chamber (16), a valve (32) for releasing fluid from the inflatable chamber (16), and a controller (41) for controlling the valves (31, 32). The controller (41) is remotely controllable from outside the patient.