Chronic respiratory diseases account for high morbidity and mortality, with asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) being the most prevalent globally. Even though the diseases increase in prevalence, the exact underlying mechanisms have still not been fully understood. Despite their differences in nature, pathophysiologies, and clinical phenotypes, a growing body of evidence indicates that the presence of lung microbiota can shape the pathogenic processes underlying chronic inflammation, typically observed in the course of the diseases. Therefore, the characterization of the lung microbiota may shed new light on the pathogenesis of these diseases. Specifically, in chronic respiratory tract diseases, the human microbiota may contribute to the disease’s development and severity. The present review explores the role of the microbiota in the area of chronic pulmonary diseases, especially COPD, asthma, and CF.