The aim of the present study was to determine the antiallergic and anti-inflammatory properties of the methanolic extract from stem bark of Ailanthus excelsa Roxb (AEME). Herbal medicines are assuming greater importance in the primary health care of individuals and communities in many developed as well as developing countries and there has been an increase in international trade in herbal medicines. Ailanthus excelsa Roxb. is a tree belonging to family Simarubaceae, indigenous to central and southern India, commonly known as a plant of Heaven. In Indian system of medicine A. excelsa is used in the treatment of asthma, bronchitis, cough, cold, pain and inflammation. AEME was evaluated by using passive paw anaphylaxis, mast cell degranulation, bronchoalveolar lavage and histopathology of lungs in rat models. Dose response studies of AEME were conducted at 100, 200 and 400 mg kg-1 p.o., showing significant reduction in sign and severity of symptoms. The results reveals that AEME showed antiallergic and anti-inflammatory potential.Colegio de Farmac茅uticos de la Provincia de Buenos Aire