Purpose. The aim of the study was to evaluate and compare the physical activity patterns of preschoolers aged 6-7 years. Methods. A sample of 221 preschool children (116 boys and 105 girls) aged 6 (5.92 ± 0.30) and 7 (6.91 ± 0.25) years was recruited. Physical activity was assessed over 7 consecutive days by using pedometers to determine step counts (steps/day). Accrued anthropometric data included height, mass, and BMI. Data were compared with ANOVA to determine any significant differences between age and sex groups and the part of the week (weekday/weekend); intergroup differences were evaluated with Fisher's LSD test. A < 0.05 level of significance was adopted for all statistical tests. Results. No significant differences were found between the age groups (6- and 7-year olds). Physical activity over the 7-day period was significantly greater in the boys (13318 ± 2354 steps/day) than girls (12300 ± 2750 steps/day). Mean weekday step counts were greater among boys (13800 ± 2458 steps/day) than girls (12587 ± 2802 steps/day); this difference was statistically significant. Mean weekend steps were 12112 ± 3467 and 11579 ± 3930 steps/ day for the boys and girls, respectively. Mean weekday steps were significantly greater (p < 0.001) than mean weekend steps in both groups. The recommendation of 12000 steps/day was met by 60.6% of the sample (69.0% boys, 51.4% girls). Conclusions. Sex differences in physical activity patterns were observed in the sample of preschool children. Boys, compared with girls, were characterized with a higher physical activity level on both weekdays and weekend days. Physical activity for both sexes was lower on weekend days than weekdays. The results indicate the need for improved health literacy among parents on current recommended physical activity guidelines and the suitability of a pedometer-based assessment method.