Post-reinforcement pause was examined to determine the reinforcing value of a win, loss, and a loss disguised as a win (LDW) for gamblers at multi-line video slot machines. The study was conducted in naturalistic settings across a variety of participants, age 21 years and older. The length of the post-reinforcement pause was recorded using a stopwatch for one win, one loss, and one LDW for each participant and was measured by recording the time between the outcome delivery and the initiation of the next spin. The different times were evaluated to determine which of the three resulted in the longest post-reinforcement pause for the gamblers following the slot machine outcome. The present study replicates and extends previous research on post-reinforcement pause in slot machine gambling, and provides discussion around the clinical utility of such findings on the prevention of problem gambling. Problem gambling is an epidemic, and there are numerous variables that contribute to its development. Post-reinforcement pause is one for those factors, and the present study can help us gain a better understanding of the events that maintain problem gambling and ways to prevent it. The results of the present study found that wins are the most reinforcing to gamblers compared to LDWs and losses, and that LDWs are significantly more reinforcing to gamblers than losses, as indicated by the patterns of the post-reinforcement pause.