Obstructive lung diseases represent a major health problem worldwide due to their high prevalence associated with elevated socioeconomic costs. Bronchial asthma and chronic obstructive pulmonary disease are chronic obstructive ventilatory disorders with airway inflammation, however they are separate nosological entities based on thedifferent development, diagnostic and therapeutic approaches, and prognostic features. However, these diseases may coexist and can be defined as the coexistence of increased variability of airflow in a patient with incompletely reversible airway obstruction. This phenotype is called asthma - chronic obstructive pulmonary disease overlap syndrome. The syndrome is a clinical and scientific challenge as the majority of these patients have been excluded from the clinical and pharmacological trials, thus well-defined clinical characteristics and therapeutic approaches are lacking. The aim of this review is to summarize the currently available literature focusing on pathophysiological and clinical features, and discuss possible therapeutic approaches of patients with asthma - chronic obstructive pulmonary disease overlap syndrome. Orv. Hetil., 2016, 157(33), 1304-1313.