Objective: to explore and to substantiate the possibility of a positive effect of the hippotherapy on children with mental deficiency and to test the effectiveness of such an activity. Materials and methods. The sociological method is a survey (questioning, interviewing) and direct observation of hippotherapy classes. The survey was conducted separately among family members of mentally retarded children (12 people) and their coaches (5 people) in order to compare the results obtained. The average age of children whose relatives and coaches participated in the survey and interviewing was 8 years. Results. To assess the impact of hippotherapy on children with mental retardation, a generalized criterion was proposed, for which a comparative analysis of the impact of hippotherapy was conducted based on a survey of family members and coaches of children engaged in hippotherapy. A comparative analysis of the assessment of the impact of hippotherapy showed the greatest positive effect of classes in the development of large motor skills-83% (75%) and communication - 67% (58%). Less noticeable results were noted in the field of speech improvement – 50% (25%) and learning ability – 25% (33%). During the observation, it was noted: the formation of skills of managing their own body in children is facilitated by the complexity of riding, the need to find balance; the features of classes provide conditions for learning children, stimulate their speech, reduce behavioral problems, have a positive impact on the psycho-emotional sphere, promote social adaptation. Conclusion: based on the studied experience in the use of hippotherapy and on the conducted analysis, the positive effect of hippotherapy on children with developmental disabilities (mental retardation) is justified, the effectiveness of such classes and the positive effect of hippotherapy as an additional method of rehabilitation are proved.