One who over an appreciable period of time is prevented by physical or mental conditions from full participation in the normal activities of their age group including those of social, recreational, educational and vocational nature is a handicapped child. This chapter defines handicapped child, gives classification of handicapped child, Role of the dental assistant in managing handicapped child, Disabled accessibility guidelines. It also explains Mental retardation, Cerebral palsy, Childhood autism, Visual impairment, Hearing loss and their dental management.