Time-out is a negative punishment procedure that parents and teachers commonly use to reduce problem behavior; however, specific time-out parameters have not been evaluated adequately. One parameter that has received relatively little attention in the literature is the mode of administration (verbal or physical) of time-out. In this study, we evaluated a procedure designed to reduce problem behavior and increase compliance with the verbal instruction to go to time-out. Specifically, we reduced the time-out interval contingent on compliance with the time-out instruction. Six preschool-aged boys participated in the study. Time-out effectively reduced the problem behavior of all 6 participants, and the procedure to increase compliance with the time-out instruction was effective for 4 of 6 participants.