Aeroallergens continue to have a key role in the pathogenesis of asthma and allergic diseases and have recently received increased attention in medical research throughout the world. The prevalence of aeroallergens vary in different regions, depending on the type of climate. The aim of the present study was to determine prevalence of the sensitivity to aeroallergens among patients with asthma and allergic rhinitis (AR), based on skin prick test (SPT) reactivity in the province of Bushehr, Iran. In this cross-sectional study, 743 patients were enrolled. The participants had asthma and AR and reacted to at least one allergen with SPT. Skin prick test with standard extracts including house dust mites (HDMs), animal dander, molds and pollens were performed on patients according to the herbal geography of the area. The male to female ratio and mean age of the patients were 1.03 and 27.6± 15.4 year, respectively. Out of 567 patients with AR, the common aeroallergens were HDMs (88.5%), molds (82.9%), animal dander (79.5%), weeds (77.6%), trees (75.5%) and grass pollen (71.5%). Moreover, among 176 patients with asthma, the prevalence of aeroallergens were HDMs (90.5 %), molds (80.7%), animal dander (77.5%), weeds (73.3%), trees (73.3%) and grass pollen (67.9%). The sensitivity to animal dander, Chenopodium album and Russian thistle pollens were significantly associated with the severity of AR. Moreover, sensitivity to animal dander such as cat and feather of birds, cockroach, Bermuda grass and Chenopodium album pollens were significantly associated with the severity of asthma. The results of this study revealed that HDM was the most common sensitizing aeroallergen in patients with asthma and AR. Molds and animal dander as indoor allergens were also common aeroallergens. We suggest that the hot weather and ambient humidity in the region may be the main cause of the change in the pattern of SPT reactivity.