Skin prick testing is a common procedure used to confirm type 1 hypersensitivity in patients with allergic diseases such as rhino conjunctivitis, asthma, urticarial, anaphylaxis, atopic eczema and food and drug allergies. It has been discovered that pathogenesis of an allergic disease involves an allergen and prevalence of these allergens vary according to the region and climate, especially in case of aero allergens. The aim of this study is to determine prevalence of sensitivity to most common allergens present in patients from Riyadh province in the kingdom of Saudi Arabiadata was collected from 400 patients referred to the clinic of King Saud University hospital. The subjects were expected to react to at least one allergen with SPT. Skin prick test with standard extracts was performed according to the herbal geography of the region. The male to female ratio and the mean age of patients was also taken into account. Percentage of patients with the common allergens present was recorded. The sensitivity to specific allergens can then be significantly associated with presence of Airway allergic diseases. The results of this study revealed the most common sensitizing allergen in patients living in the region and their seasonal variation.