This manual summarizes the methodology used to develop WHODAS 2.0 and the findings obtained when the schedule was applied to certain areas of general health, including mental and neurological disorders. The manual will be useful to any researcher or clinician wishing to use WHODAS 2.0 in their practice. It includes the seven versions of WHODAS 2.0, which differ in length and intended mode of administration. It also provides general population norms; these allow WHODAS 2.0 values for certain subpopulations to be compared with those for the general population.