The aim of this study was to explore the effect of natural sport attractions on developing sport tourism in Iran. Data were collected from three groups: 1. tourism experts of Cultural Inheritance and Tourism Organization (n = 37) 2. experts of active travel agencies in the field of tourism (n = 60) 3. sport experts of ten sport federations (swimming, horse riding, hunting, track and field, skiing, golf, general sports, mountaineering, cycling and boating, n = 30). A self- administered questionnaire was distributed among samples. Finally, 112 questionnaires were filled out. The data were analyzed by factor analysis. From the viewpoint of these three groups of experts, "attractions related to hiking" (load=0.79), "attractions related to shore, water and summer sports" (load =0.78), "attractions related to deserts and salt deserts" (load=0.75) and "attractions related to hunting" (load=0.75), were of the greatest importance in sport tourism development in Iran. Findings of this research showed that those attractions which were less affected by seasonality in Iran and as a result had longer sport tourism season and various activities were provided during those attractions, are of the great importance in the development of sport tourism in Iran.