Introduction. Evidence for the clinical utility of bronchoalveolar lavage (BAL) galactomannan in the management of fungal disease outside of haemato-oncology patients is limited. Aim. To determine how the introduction of BAL galactomannan testing impacted on the diagnosis and management of invasive aspergillosis and other fungal diseases in non-haemato-oncology patients. Methodology. Retrospective review of all adult patients (age ≥16 years) without a diagnosis of haematological malignancy who had a positive BAL galactomannan from 1 November 2014 to 30 April 2018. Using electronic patient records we obtained demographic data, clinical details, laboratory investigations, relevant radiology and antimicrobial history for each case. Results. In total, 121 episodes with a galactomannan OD index of ≥0.500 were included in the study; 29 cases (24 %) were felt to reflect fungal disease. Antifungal therapy was commenced as a direct consequence of a positive BAL galactomannan result in 13 patients where the ultimate diagnosis was subsequently considered to be non-mycological: associated medication-related side-effects in this group included deranged liver function tests (n=3), rash (n=1) and fever (n=1), related to amphotericin B (n=1) and voriconazole (n=4). Conclusion. We show that vigilance is required when interpreting galactomannan results in non-haematology patients to avoid potentially harmful overtreatment.