The use of behaviouristic techniques in language therapy is discussed. Special emphasis is placed on the practical problems of assessing language from a behaviouristic standpoint and on implementing suitable treatment techniques. A selective review of research with children and adult aphasics is presented, and it is concluded that the application of behaviouristic techniques is effective in a variety of cases. The possibility of using friends and family in therapy and the importance of adapting treatment to the subject’s natural environment are raised for further discussion.