Three experiments investigated the role of sensory feedback in controlling drinking elicited in satiated rats by injecting a solution containing 24 x 10-10 moles of carbachol directly into the lateral preoptic area. After free access to water, drinking stopped in 20 min. But time-response curves measured either by delaying access to water or by recording licking reinforced on a variable-interval schedule showed that thirst induced by carbachol fell off gradually over a period of at least 1 hr. Thus, stopping after 20 min. of drinking was produced by feedback from drinking, rather than by dissipation of the drug. Another test showed that feedbacks from both mouth and stomach regulate carbachol-induced drinking as they do deprivation-induced drinking.