Independent associations between personal- and demographic characteristics and physical activity in 3-6 year old children attending preschool were identified in this study. Boys spent a larger proportion of the time on moderate-and-vigorous physical activity (MVPA; p < .001) and had a higher total physical activity level compared with girls (p < .001). The 3-4 year old children spent less time on MVPA and had a lower total physical activity level compared with both 4-5 (p < .01) and 5-6 year old children (p < .001). The individual preschool, gender and age of preschool children were strong predictors of physical activity (R2-total model=(0.36-0.39)) during preschool attendance.