Physical activity (PA) in children/adolescents of both genders from a rural community in Mozambique was estimated by accelerometry and by questionnaire and was compared with PA of Portuguese youth. Total PA, moderate (MPA), vigorous (VPA) and very vigorous (VVPA) were evaluated. Mozambican boys were more active than girls. Intensity of PA declined significantly with age. Survival activities, such as household tasks, were the predominant mode of PA. Compared with Portuguese children/adolescents, Mozambicans had significantly higher total PA; showed less decline of PA with age and engaged in fewer minutes at higher intensity PA. Environmental factors likely explain documented differences.