The paper reviews research on the development of communication in visually and mentally handicapped persons. Communication difficulties are traced from the preverbal stage, through imitation and turn-taking, visual co-orientation and objects, and the effects of visual loss on early development. The added impact on a mentally handicapped person of a visual handicap is assessed. The importance of features in the physical environment (such as sound sources and echoes) for communication development are noted. Additional behavior problems of persons with visual and mental handicaps are described; these include self-injury and stereotyped behavior. (CL)