The prevalence of allergies has increased in all parts of the world. The present study was conducted to determine the prevalence of sensitivity to common aeroallergens, pollen, thresher dust and cotton dust, in Pakistan. Retrospective cohort study. Record of 65067 who attended the Allergy Centre, National Institute of Health, Islamabad, Pakistan from January 2007 to August 2008 was retrieved. Subjects that were skin prick test (SPT) negative and those that were SPT positive to aeroallergens were extracted and subcategorized on the basis of the 8 provinces of Pakistan, including, Islamabad Capital Territory, Punjab, Baluchistan, Sindh, Northern Areas, Kashmir, North Western Frontier Province (NWFP) and Federally Administered Tribal Areas (FATA). Monthly analysis of prevalence of allergies was also determined. Of the total, 68.6% were SPT positive. The highest number of affected individuals was from the Punjab region (41%). The highest number of cases of all aeroallergens was reported in the month of August (3532, 13.7%). Significant high correlations were observed between mixed pollen, thresher dust and raw cotton and allergic rhinitis, asthma, uriticaria and allergic conjunctivitis. There was no significant correlation between allergen sensitivity and atopic edema. A high prevalence of sensitivity to aeroallergens is observed in the Punjab Province of Pakistan.