The time course of the changes in hedonic response following ingestion of three different foods was investigated. Normal weight, non-dieting female subjects rated the pleasantness of the appearance, smell, texture and taste of nine foods and then consumed as much as they wanted of cheese on cracker, tomato soup or orange jello. After this first course, subjects re-rated the pleasantness of the foods at 2, 20, 40 and 60 min. Following the 60 min rating, subjects were offered a second course of cheese on cracker or chocolate bar. For all sensory variables measured and for all foods consumed, the greatest decline in pleasantness occurred for the eaten food 2 min after consumption. For the food rate as most palatable (cheese on cracker) there was some recovery of pleasantness of the texture and taste over the hour. Intake in the second course was similar regardless of whether the food offered was different or the same as the food consumed in the first course. Since changes in the pleasantness of the foods occurred rapidly for all sensory variables studied and since the magnitude of these changes did not increase over time, it is concluded that the development of sensory-specific satiety is related primarily to the sensory stimulation accompanying ingestion as opposed to the postabsorptive effects of consuming these foods.