This chapter discusses the lung in the setting of collagen-vascular/connective-tissue diseases (CTDs) other than rheumatoid arthritis (non-RA). It explores the initial issues to consider while approaching a patient with a possible collagen vascular disease in pulmonary practice, and discusses how a particular clinical presentation may be correlated with a specific CTD. It examines the diagnostic considerations when patients with known CTDs develop new clinical manifestations related to any of the compartments of the lung (pleural, parenchymal, interstitium) and provides information that may help incorporate into a rational plan for their assessment. It enumerates the conditions to consider when patients with CTD develop symptoms (such as dyspnoea) in the presence of normal chest x-rays and discusses aspects of diagnostic relevance in pulmonary hypertension and interstitial lung disease related to CTDs. It also discusses the role of autoantibodies in specific diagnosis, and the issues involved in the interpretation of lung biopsy specimens. A discussion on pulmonary issues in rheumatoid arthritis (RA) appears in the foregoing chapter. A subsequent chapter is dedicated to the role of serological tests in CTD-associated interstitial lung disease.