Introduction: Cognitive decline is one of the basic problems of adults, the cost of diagnosis and treatment is high, and despite the high importance of physical and mental health in facing this disease, no comprehensive research has been done on the role of psychological well-being and sports history on this disorder.  
Aim: The purpose of the research was to design a model of the mediator role of psychological well-being in the causal relationship between sports history and mild cognitive impairment.
Method: This research was applied and correlational. The statistical population was 55 to 84-year-old men of Tehran with a history of physical activity, and 396 of them were selected based on criteria. The research tools were Wechsler's working memory test software (1945), Reif's psychological well-being questionnaire (1989), and self-reported sports history questionnaire. To analyze the data, descriptive statistics were used in spss23 and structural equation modeling and Sobel tests were used in smartPLS3.1.1 at a significance level of 0.05.
Results: Psychological well-being has a positive and significant relationship with sports history (p=0.001; t=23.280) and working memory (p=0.001; t=18.227). Also, sports history has a positive and significant relationship with working memory (p=0.001; t=31.429) and the research model has a good fit and psychological well-being plays a mediating role in the relationship between sports history and working memory (p=0.001; t=10.55).
Conclusion: Engaging in proper physical activity and having psychological well-being can reduce the amount of mild cognitive impairment in adults, so these people should always think about their physical and mental health.