Introduction: Human resources are considered as the largest and most valuable capital of any organization. Prison staff are more under pressure because of the especially closed environment and working conditions. Life satisfaction is an indicator of the assessment of living conditions from the point of view of individuals, which affects all aspects of the person's physical, emotional and social life domains. few researches have been done on life satisfaction for prison staff. The aim of this study was to the study of correlation between Sports participation and BMI with life satisfaction of Tonekabon prison staff. Methodology: This research was carried out using descriptive-survey method, which according to the purpose of the research was an applied research type. Its data was gathered by field method. The statistical population of the study consisted of 60 Tonekabon prison staff. The sample size was considered as a whole and equal to the size of the community. 52 questionnaires were useful for analysis. To collect the research data, a demographic questionnaire and a life satisfaction scale questionnaire from Diener et al. were used to measure sports participation using Sharkley questionnaire. To calculate BMI we used a weight-kilogram scale divided by height-meter squared. Cronbach's alpha for the life satisfaction questionnaire was 0.86 which indicates the reliability of this questionnaire. To analyze the data, SPSS software version 24 was used to describe the profile of respondents as well as inferential method of Pearson correlation coefficient for correlation and regression analysis was used for prediction. Results:The findings showed that there was no significant correlation between body mass index and their life satisfaction. But there was a correlation between the amount of sport participation and their life satisfaction (p <0/05). The marital status did not have a significant role in satisfying the lives of these prison staff, but the size of the BMI in sin
