This mixed method paper explored the effect of family structure on children's physical activities and sedentary pursuits. It furthers the limited understanding of how family structure impacts on children's time in, and reasons behind engaging in, certain physical activities. Children from three inner city comprehensive schools in the Midlands, United Kingdom, participated through questionnaires (n = 381) and semi-structured interviews (n = 62). The results indicated that boys and girls from single parent families spent more time in sedentary activities during the week and at the weekend (P less than 0.01) when compared with their intact couple family counterparts. It was identified that children in single-parent families received less parental support due to a lack of time, transport and additional parental responsibilities that created a family environment that encouraged sedentary pursuits. Moreover, the barriers that encouraged sedentary activities also prevented children in single parent families from engaging in lifetime activities during the week. Children from intact couple families recorded more time in lifetime activities than those in single parent families (P less than 0.01). Finally, children in two-parent families had more opportunities to engage not only in these activities individually but also in joint activities with their parents, further reinforcing these behaviours. (Contains 4 tables.)