A synchronous-reinforcement schedule is a type of schedule of covariation in which the onset and offset of the reinforcer covaries with the onset and offset of behavior. This study was a proof-of-concept demonstration of the efficacy of synchronous reinforcement for on-task behavior (completing a preacademic skill) and an evaluation of preschoolers' preference for this schedule in comparison to a more traditional schedule of reinforcement. Specifically, we compared the effects of a synchronous-reinforcement schedule to one in which continuous access to stimuli was delivered at the end of the session and yoked to the duration of on-task behavior that occurred during the session (accumulated reinforcement). Results showed the synchronous-reinforcement schedule was more effective for increasing on-task behavior and preferred by most participants.