The superficial regions of the left vagus nerves of a dog were selectively stimulated with 39-electrode spiral cuffs having 13 circumferential groups of three electrodes (GTE) to modulate the function of the innervated internal organs and glands. Under general anaesthesia, the cuffs were chronically implanted around the nerve in the neck in two adult Beagle dogs and remained viable for 16 months. The regions were stimulated with biphasic, rectangular current pulses (2 mA, 200 micros, 20 Hz) delivered to the group of GTE lying close to the region innervating the specific internal organs or glands. The results showed that specific electrode configurations had actions on the heart (GTE 9), lungs (GTE 4) and pressure in the urinary bladder (GTE 1). It was also shown that GTE no. 10 significantly modified the endocrine function of the pancreas. The results of this study clearly demonstrate that internal organs and glands can be selectively stimulated via the selective stimulation of innervating superficial regions of the autonomous peripheral nerve.