The aim of this study was to analyze the effect of mental fatigue on passing decision-making in professional soccer athletes. A controlled and counterbalanced cross-over design was adopted consisting of three visits with a 1-week interval between sessions. Twenty (20) professional soccer male athletes participated in three randomized conditions divided into three visits: control, 15-min Stroop task, and 30-min Stroop task. Inhibitory control was accessed by the Stroop task (accuracy and response time) before and after induced mental fatigue protocol. The athletes played a training match (90-min) following the experimental conditions. The Game Performance Assessment Instrument (GPAI) was used for the passing decision-making analysis. The GPAI analysis showed impaired passing decision-making performance following the 30-min Stroop task compared with the 15-min and control condition (F= 6.99, p = .01). Moreover, an increase in response time during the Stroop task was found following 30-min Stroop task condition (F = 6.57, p = .03) compared to 15-min of Stroop task and control conditions. Prolonged cognitive tasks may be considered a mediating factor in passing decision-making performance in male professional soccer athletes throughout a full-length training match. Thus, athletes should avoid highly demanding-cognitive tasks before a soccer match. Future studies are required to explore more ecological cognitive tasks to induce mental fatigue (i.e. smartphones and video-games) and their effects on other performance indicators (e.g., physical, technical, tactical) in a full-length training match setting.