The aim of this research is to determine the relationship of the unethical behavior of the trainer with the mental endurance of the athlete according to the perceptions of wrestling athletes. In the study, the Personal Information Form created by the researchers, the Athlete Perception Scale Related to Unethical Behavior of the Coach developed by Güven ve Öncü (2012) and the Mental Endurance Inventory developed by Sheard, Golby and Van Wersch (2009) and adapted to Turkish by Altıntaş (2015) were used as data collection tools to learn some demographic information of the participants. Descriptive statistics, t-test, one-way analysis of variance (ANOVA), tukey multiple comparison, Pearson correlation tests were used in the analysis of the data. As a result of the findings obtained, while there was no significant difference in terms of gender variable of unethical behavior of coaches and mental toughness of athletes according to the perceptions of athletes, there was a meaningful difference in terms of marital status variable of athletes. According to the perceptions of athletes, unethical behavior of coaches; while notable differences were observed when the athlete's age, education level, parents' education level were evaluated in terms of sports year variables, mental toughness of athletes was not remarkably dissimlar when the athlete's age, education level, parents' education level were evaluated in terms of sports year variables. According to the result of the correlation analysis between the Athlete Perception Scale Related to the Unethical Behavior of the Coach and the Mental Toughness Inventory in Sports, it can be explained that there is a midlevel relationship negatively. As a result, it can be stated that the mental toughness of the athlete increases as the unethical behavior of the coaches decreases.