This study aims to determine situation of the prevalence of disabilities and the accessibility to health, education and social services of children with disabilities in the communities of Thailand. Mixed-methods of data collection were used. A community survey by a team of psychiatrists and clinical psychologists was conducted to estimate the prevalence of 7 disabilities in children aged between 2½ and 12 years in nine sub-districts of nine sampled provinces (except Bangkok) during October 2014-July 2015. Altogether, 6,334 children were investigated. Qualitative data were collected from home visit, in-depth interview, non-participant observation, and focus group discussion with parents and teachers of the children identified as having disability, and also with health care providers to explore problems of unmet demands. Results show that 66% of children aged 2½-12 were found normal, yet, 13% had at least one disability of which learning disability was most prevalent, and 21% with physical, psychological or behavioral problems. The availability of health services for children with disabilities in each area varied due to inadequacy or lack of type of health professionals. Community hospital is not allowed to recruit rehabilitation specialists, though policy on disability service provision is assigned to. The study also found that the term “disability” contained stigma connotation and was rejected by well-to-do and educated parents. When compared with the accessibility to service database of the Ministry of Social Development and Human Security, the National Health Security Office, and the Ministry of Education, this study showed much higher number children with disability in communities reflecting that there are still more unregistered children and inaccessible to necessary public services. The un-integrated and difficult-to-access service structure, poverty, cultural beliefs, and social unawareness are among factors that cause unmet demands. Main recommendations for concerned agencies are an urgent policy and program to increase access to care to reduce unmet need in children with disabilities and the integration of disability policy into the strategy to reduce poverty.