The aim of this study was to investigate the effect of music with different tempos (fast and slow) on the speed and accuracy of decision-making in semi-skilled football players from the University of Tehran with poor sleep quality. This research employed a quasi-experimental pretest-posttest design with a control group. The participants were 45 male semi-skilled football student-athletes aged 19 to 31 years who were randomly assigned to three groups of 15: fast music, slow music, and control. The instruments used included the Pittsburgh Sleep Quality Index (PSQI) and a computer-based decision-making software. After completing a decision-making pretest, participants in the two experimental groups listened to an instrumental music piece with different tempos. Following a one-minute rest, the posttest was administered. Results from repeated measures ANOVA revealed that both fast and slow music significantly improved decision-making speed and accuracy compared to the control group. Moreover, fast-tempo music had a greater effect on increasing decision-making speed, while no significant difference was found between fast and slow music in terms of decision-making accuracy. These findings suggest that music can serve as an effective stimulus to enhance cognitive performance and decision-making in athletes with poor sleep quality.