ALTER, European Journal of Disability Research 9(2015)317–330. The purpose of this paper is to describe the varying scope and content of data collection instruments on child disability and to provide a historical snapshot of the rates of reported disability among children. A total of 716 data sources were identified, corresponding to 198 countries covering more than 95% of the world’s children. The findings reveal a lack of consistent definitions and measures of disability, which contribute to major challenges in producing reliable and comparable statistics.