Asthma and chronic obstructive pulmonary disease (COPD) are increasing in incidence, prevalence and burden worldwide. Although asthma and COPD may share overlapping features, they are distinct clinical entities whose differences affect management and prognosis. This review emphasises the epidemiologic, etiologic and clinical distinctions to guide physicians in differentiating asthma from COPD. Establishing the correct diagnosis is the first step towards individualized disease management plan that will optimise the quality of life and physical well being of patients with asthma and COPD.