The objective of the study was determination of the effect of various forms of physical activity, BMI, and time devoted to computer games on the level of Health-Related Physical Fitness (H-RF) in 6-7-year-old children from Polish rural areas. The study covered 25,816 children aged 6-7: 12,693 girls and 13,123 boys. The evaluations included body height and weight, and 4 H-RF fitness components (trunk strength, explosive leg power, arm strength and flexibility). The BMI was calculated for each child. The Questionnaire directed to parents was designed to collect information concerning the time devoted by children to computer games, spontaneous and additional physical activity. The strength of the relationships between dependent and independent variables was determined using the Spearman's rank correlation (RSp), and the relationship by using the regression analysis. The BMI negatively affected the level of all the H-RF components analysed (p=0.000). The negative effect of computer games revealed itself only with respect to flexibility (p=0.000), explosive leg power (p=0.000) and trunk muscle strength (p=0.000). A positive effect of spontaneous activity was observed for flexibility (p=0.047), explosive leg power (p=0.000), and arm strength (p=0.000). Additional activity showed a positive relationship with trunk muscles strength (p=0.000), and explosive leg power (p=0.000). The results of studies suggest that it is necessary to pay attention to the prevention of diseases related with the risk of obesity and overweight among Polish rural children as early as at pre-school age. There is also a need during education for shaping in these children the awareness of concern about own body, and the need for active participation in various forms of physical activity.