The interaction of endogenous opiates and stress-induced eating in rats was evaluated by pharmacological manipulation. Eating induced by the tail-pinch method was inhibited by the opitate antagonist naloxone; after being repeatedly stressed over a 10-day period and then given nalozone, the rats behaved in a manner indistinguishable from the "wet-dog" shakes of opiate withdrawal. Thus endogenous opiates may have a role in the control of stress-related eating, a finding that may have therapeutic implications for humans.