Tackling gender inequalities has become central to poverty reduction strategies, including the Millennium Development Goals (MDGs). However, gender dynamics between children growing up in poverty, and how these change over time, are poorly understood, yet a number of assumptions prevail. Young Lives is a study of childhood poverty which is following two cohorts of children over 15 years in Ethiopia, India (Andhra Pradesh), Peru and Vietnam. Analysis of Young Lives data challenges assumptions and suggests that gender is one source of inequality, alongside poverty, geographical location, ethnicity or caste status, which can intersect to impact negatively on children's life chances and on girls differently from boys. To improve equality of life chances, policy interventions will have most success by targeting absolute poverty and broader structural inequalities.