A controlled trial of the effectiveness of family therapy for asthmatic children has been completed, and the results indicate that family therapy may have a part to play in the management of asthma. Our observations have shown that an interaction of psychosocial factors can have a significant effect on the course of the asthma by setting up a circular system which may ultimately lead to clinically intractable asthma, as well as intense emotional distress. Treatment is based on an understanding of the interactional model with the aim of interrupting the progressive sequence of events. A family approach is indicated when (1) emotional factors seem to be playing a significant part; (2) the asthmatic child is manifesting behaviour problems; (3) there is evidence of family psychopathology or (4) the asthma is not being reasonably well controlled with conventional methods of management.In this paper we are concerned with the families of asthmatic children, and we examine the effect the asthma has on the family and the effect the family has on the asthma. We also discuss techniques of intervention in such families. Certain assumptions are implicit :(1) Asthma is primarily a diffuse obstructive disease of airways characterized by a high degree of reversibility with appropriate therapy (Vaughan and McKay, 1975). (2) Although asthmatic children may present certain personality traits (e.g. timidity, lack of self-assertion, sensitivity, obsessional features) there is no specific personality structure amongst such children