Connective tissue disorders correspond to a heterogeneous group of inflammatory diseases characterized by abnormal immune system activity leading to connective tissue alterations in multiple parts of the body. In adults, connective tissue disorders include rheumatoid arthritis, progressive systemic sclerosis, Sjögren syndrome, systemic lupus erythematosus, dermatomyositis and polymyositis, ankylosing spondylitis, and mixed connective tissue disease. Broncho-pulmonary involvement may be variable with involvement of all anatomical components of the lung. Involvement of other intrathoracic structures (pleura, respiratory muscles, heart, rib cage) is frequent. The most specific manifestations include interstitial lung diseases and pulmonary hypertension. During follow-up, progressive respiratory diseases may occur due to the treatment, infections, pulmonary embolism or neoplasms.