The aim of this study was to describe the prevalence of disabilities according to demographic and socioeconomic characteristics, as well as to determine the main causes. The research used data from two population-based health surveys in São Paulo State, Brazil, in 2002 and 2003, designed with complex sampling techniques. Interviewees that reported disabilities comprised the study sample, according to the database variables. Prevalence of any disability was 110.8; visual disability, 62; hearing disability, 44; and physical disability, 13.3. Prevalence rates for disabilities varied according to age, gender, and schooling. Prevalence of hearing and physical disability was higher among men. The principal cause of disabilities was the disease itself. External causes were also one of the causative factors in disabilities. Disabilities increased with age and were more prevalent among women and persons with less schooling, and the principal causes were diseases and injuries.