This observational study aims to investigate the association between brain type, determined by the second-to-fourth digit (2D:4D) ratio, playing position, and mental toughness among amateur soccer players. A total of 270 licensed amateur soccer players participated in the study. Mental toughness was assessed using the Sports Mental Toughness Questionnaire (SMTQ), while brain type was determined by measuring the 2D:4D digit ratio. The study examines whether mental toughness differs according to brain type and playing position, providing insight into the neuropsychological characteristics of soccer players and their potential relationship with psychological performance.