RESULTS: A total of 184 patients with chronic airway disease with complete clinical data were reviewed, 93 (50.5%) were males while 91 (49.5%) were females. Seventy four (40.2 %) had asthma and 110 (59.8 %) had COPD. The prevalence of ACOS among patients with chronic airway disease was 4.9% and it was 8.2% among those previously diagnosed with COPD. The mean age of patients with ACOS was 58.4± 8.6 with a median duration of illness of 7.5 years (interquartile range 3-23). Five of the patients with ACOS were males, had history of tobacco smoking and use of biomass fuel for cooking respectively. One third (33.3 %) of the patients had history of occupational exposure to dust and chemical irritants. In terms of pattern of symptoms, 2 had predominantly asthma symptoms and 3 had predominantly COPD symptoms while 4 had overlapping symptoms of asthma and COPD.