House dust allergy is very common in Eastern Massachusetts. The house dust mite is a major allergen in both bronchial asthma and perennial allergic rhinitis especially in children and adolescents. Environmental control measures in the bedroom are very helpful in reducing allergic symptoms in many patients. In selected cases immunotherapy with D. farinae appears to be helpful. There is an urgent need for the availability of a safe chemical to decrease mite population in the home. More immunological studies are needed on mite allergy and mite immunotherapy.