BACKGROUND: Moderate-to-vigorous physical activity (MVPA) plays an important role in childhood overweight prevention. Sedentary time appears to be independently associated with overweight, but most research has been done in adults. OBJECTIVE: The objective of this study were to identify subgroups of children based on their MVPA and sedentary time, and explore differences in body mass index (BMI), waist circumference and overweight prevalence between among these subgroups. METHODS: A sample of 766 10- to 12-year-old children (52.9% girls, 11.6 ± 0.8 years) were recruited from Hungary (n = 158), Belgium (n = 111), the Netherlands (n = 113), Greece (n = 169) and Switzerland (n = 215). Children wore an accelerometer to measure MVPA and sedentary time. RESULTS: Cluster analysis revealed four clusters in both gender groups showing an unhealthy pattern (low MVPA/high sedentary time), a healthy pattern (high MVPA/low sedentary time), a low mixed pattern (low MVPA/low sedentary time) and a moderate to high mixed pattern (moderate to high MVPA/moderate sedentary time). In girls, the high MVPA/low sedentary time cluster had a significantly lower BMI (P ≤ 0.05), a lower waist circumference (P ≤ 0.01) and the lowest percentage of overweight (P ≤ 0.10) compared with the other three clusters. In boys, both clusters with higher activity levels had a significantly lower BMI (P ≤ 0.001) and waist circumference (P ≤ 0.001) than the two low activity clusters, independent of sedentary time. CONCLUSION: Engagement in more MVPA and less sedentary time is associated with a more favourable weight status among 10- to 12-year-old girls. Among boys, MVPA seems most important for weight status, while sedentary time appears to be less relevant.