International comparisons of poverty are usually built on absolute monetary poverty indicators. The World Bank has promoted the most known and used indicator throughout the world, one of the target indicators in the Millenium Development Goals (MDGs), based on a poverty line estimated at 1,90$/day in pps. This approach bears the advantage of simplicity, but has numerous limitations (short term vision, totally monetarised economy…). Some countries therefore prefer, including for international comparisons, developing their own poverty threshold, more contextualised. Multidimensional indicators are also in use (HDI, MPI) to go beyond an exclusively monetary approach of poverty. A reflexion on finer indicators representing the poverty found within households and for specific categories of population, with specific needs, such as older persons or children, is little developed. In order to challenge the way social policies address child poverty, -we briefly describe how countries and international organisations have dealt with the issue of measuring child poverty -we identify, through three very different case studies (Uganda, Russia, France), the main limitations of international comparisons