The UN Convention on the Rights of the Child and ILO Convention No. 182, two of the main international legal instruments relating to child labour, both recognise children’s right to be protected from forms of work that adversely affect their health and development, regardless of whether this activity is economic or non-economic, market or non-market, in nature. But these norms have not been translated into a universally-accepted statistical definition of child labour. Widely differing positions prevail among researchers about what kind of activities performed by children should be classified as children’s work, and progressively, as child labour. The current study forms part of a broader research effort directed towards arriving eventually at an internationally acceptable consensus on the statistical definition of child labour. It looks specifically at children’s non-market activity, its classification (i.e., economic or non- economic), its impact on health and education outcomes, and at some of the issues linked to the inclusion of non-market activity in the definition of child labour. The study should be seen as an initial contribution to the discussion, aimed at raising key measurement questions requiring further investigation and deliberation.