Lower respiratory tract disease (LRTD) is common in parrots, raptors and passerines. However, it can be difficult to recognize because presenting signs are often non-specific and frequently not obviously respiratory. This chapter deals with the clinical signs, therapeutic approach, diagnostic techniques and indications for diseases involving the lungs and air sacs. Case examples: Glossy Black Cockatoo with clinical chlamydiosis; Green-winged Macaw with aspergillosis and Escherichia coli infection; Thin Cockatiel with dyspnoea; Foreign body ingestion in an African Grey Parrot.