Chronic productive cough in the context of exacerbations of airway disease can be associated with positive sputum cultures for fungi, in particular Aspergillus fumigatus and Candida spp., suggesting fungal bronchitis, a condition not widely recognised, as a possible cause for the exacerbation. Our objective was to determine the response to antifungal therapy in patients with suspected fungal bronchitis. Retrospective analysis of data extracted from case records of patients under secondary care respiratory clinics who had been treated with triazole therapy for suspected fungal bronchitis between 2010–2017. Primary outcome was lung function response after 1 month of treatment. Nineteen patients with fungal bronchitis due to A. fumigatus and 12 patients due to Candida spp., were included in the study. Most of the patients, particularly in the Aspergillus group, had allergic fungal airway disease on a background of asthma. All but one of the patients in each group were recorded as showing clinical improvement with antifungal therapy. In the majority of patients this was reflected in an improvement in lung function. Aspergillus group: FEV1 (1.44 ± 0.8 L vs 1.6 ± 0.8 L: p < 0.02), FVC (2.49 ± 1.08 L vs 2.8 ± 1.1 L: p = 0.01), and PEF (260 ± 150L/min vs 297 ± 194ml/min: p < 0.02). Candida group: FEV1 (1.6 ± 0.76 L vs 2.0 ± 0.72 L: p < 0.004), FVC (2.69 ± 0.91 L vs 3.13 ± 0.7 L: p = 0.05), and PEF (271± 139L/min vs 333 ± 156 L/min: p = 0.01). Side effects of treatment were common, but resolved on stopping treatment. This service improvement project supports the idea that fungal bronchitis is a distinct clinical entity which is responsive to treatment. Controlled clinical trials to confirm the clinical impression that this is relatively common and treatable complication of complex airway disease are required.