AbstractHot tub lung (HTL) is a type of Hypersensitivity Pneumonitis (HP) caused by inhalation of aerosols containing non‐tuberculous mycobacteria (NTM). We report the first case of hot tub lung in Victoria, Australia. A 31‐year‐old female presented with 3 weeks of dyspnoea, fevers and malaise, despite a course of antibiotics. She had used an indoor spa frequently for the past several months. She was hypoxic saturating 86% on room air. Examination revealed fine bilateral basal crepitations without wheeze. Inflammatory markers were elevated. A high resolution CT (HRCT) chest demonstrated extensive bilateral ground glass changes and centrilobular nodular opacities involving upper and lower zones. Bronchial washings were obtained and isolated Mycobacterium Avium Complex. Clinically, the patient had excellent response to empirical corticosteroids and avoidance of hot tub. This case highlights the importance of clinical history taking and suspicion of Hot Tub Lung as a differential diagnosis in a patient with a compatible clinical history, radiology and microbiology and exposure to a hot tub.