Abstract: Diet and physical activity are principal determinants of nutritional status and energy balance. Low physical activity has been shown to be one of the risk factors for development of obesity in children. One's physical activity as a child is a predictor of physical activity level as an adult. This study was aimed at describing the type, frequency and duration of physical activity and their association to BMI-for-age status of school-age children in Tamale. In this cross-sectional study, a sample of 400 school-age children was selected from randomly selected schools in Tamale, Ghana. The physical activity questionnaire for children (PAQ-C) was used to assess physical activity levels. Anthropometric measurements of age, weight and height were measured and computed to determine the adiposity status of the children. More than 80% of the studied children engaged in moderate to heavy type of physical activity. By frequency, 88.3% of boys and 75% of girls participated in a physical activity at least 2 times a week. During leisure times, more boys than girls played football and more girls than boys watched television. A significant proportion of the children engaged in heavy type of physical activity with increase in age. An overweight/obesity prevalence of 8.5% was found. A large proportion of the children reported being in the moderate to heavy type of physical activity. Type, frequency and duration of physical activity were associated to age. A double burden (overweight vs. underweight) of malnutrition was found.