Over the last few years, the importance of sport in everyday life has rapidly increased. Asthma and allergic rhinitis are among the most common problems to be afforded in those practising sports. It is believed that allergy represents a limitation to sport activity, but many elite athletes suffer from respiratory allergy: within those participating in the Olympic Games, 49% suffered from allergic rhinitis, and 20% of winter sport athletes suffered from asthma. Exercise is a potent trigger factor for asthma both in allergic and non allergic subjects. About 70% of asthmatic patients experience asthma symptoms during exercise; skiing and running in particular can elicit bronchospasm. Swimming is usually considered a non asthmogenic sport, but the inhalation of chloride derivatives and irritants can favor asthma onset. From a pathogenic point of view, exercise induced asthma seems to be due to sudden changes of osmolarity in the mucus layer on bronchial walls induced by hyperventilation and low temperature of inspired air. Athletes also suffer from non allergic rhinitis that can influence their performance. Rhinitis in fact modify the correct ventilation and can induce lower respiratory disorders, like asthma. Recently, cold-induced rhinitis has been described in those athletes practicing winter sports, especially skiers. This rhinitis is characterized mainly by rhinorrhea, and responds to topical anti-cholinergic agents. In conclusion, sport can exacerbate or induce asthma and rhinitis but this fact does not represent a limitation to physical activity. A deep knowledge of the diseases occurring during exercise, a detailed education and a correct therapy, allow to perform sports even at high levels also in presence of respiratory allergy.