The purpose of this study was to describe the sex-specific patterns of preschooler's daily pedometer-determined physical activity (PA) during (DS) and after (AS) school hours. Τhe random sample of the one hundred and forty four children (71 boys and 73 girls, age = 5 - 6 yr), who attend the kindergartens in Greece, wore pedometers for four days (3 school days and 1 weekend day) and recorded steps during school and after school hours. For the statistical analysis of the data, ANOVAs repeated measures were used. From the results gender seems to be the main effect (F1.142 = 14.937, p < .05) on children's PA. Βoys took significantly (F1.143 =11.193, p=. 001) more steps per day than girls: 5.735 ± 2.820 vs 4.337 ± 2.159 during school. Furthermore, boys took more steps per day than girls: 11.353 ± 5.319 vs 9.586 ± 4.254 steps per day. Consequently, these data give an understanding of the sex-specific patterns of preschoolers' daily pedometer-determined physical activity (PA) during (DS) and after (AS) school hours.