The aim of this study is to identify the relationship between BMI, physical activity, and hours of watching TV in preschool aged children. The sample consisted of 102 children (49 boys and 53 girls) aged 48 to 79 months (Mean=60.67, S.D.=7.07). Physical activity was measured using an OMRON walking style II pedometer, while hours of TV watching and occupation with “digital” games were recorded using a parent questionnaire. Differences between groups were assessed using one way analysis of variance (ANOVA). From the results was not found any statistically significant effect of BMI in number of steps/week (F =.411, p=.672), in number of covered km/week (F=.411, p=.673) and in hours of TV watching/day (F=.004, p=.996). However, statistically significant difference was found in the level of physical activity between children that watched less than 1h TV per day, (number of steps/week: Mean=61426.75, SD=10766.28) and total km/week: Mean=24.54, SD=4.31) and children that watched above 5h TV per day, (number of steps/week: Mean=37753.25, SD= 2975.89 and km/week: Mean=15.07, SD=1.18). Consequently, ΒMI is not a perfect predictor for preschool aged children to show any differentiations in relation to older children. However a negative association is possible to exist between physical activity and hours of TV watching at a sensitive time period.