This article reviews the theoretical basis and methods for disability measurement. Different methods arise from different theoretical perspectives. Recent efforts to develop a general international disability measure consistent with the social model of disability aim to produce an internationally comparable measure of disability with which to assess the equalisation of opportunities. Such a measure cannot consistently identify disabled people in need of health and social services. Correctly identifying those in need of these services particularly concerns developing countries where government revenues and disability services are severely limited. This review highlights the need for multiple disability measures to meet different purposes of measurement. The Washington Group general measure on disability and Katz's Activities of Daily Living Index are recommended as valid measures of varying functioning level consistent with the International Classification of Functioning, Disability and Health.