A 61-year old woman was admitted with increasing dyspnea and deranged liver function tests. A chest X-ray revealed small volume lungs with reticulo-nodular shadowing. High resolution computed tomography of the chest revealed interlobular septal thickening. The patient subsequently underwent an open lung biopsy and ultrasound-guided liver biopsy, which were consistent with a hypersensitivity pneumonitis and drug-induced liver injury respectively. The patient had previously been commenced on lansoprazole 10 days before the onset of symptoms; this had been stopped at diagnosis. High dose prednisolone was commenced, and the patient went on to make a full recovery. Hypersensitivity pneumonitis is a form of interstitial lung disease that is rarely associated with lansoprazole; this is the first report of it causing an idiosyncratic reaction affecting the lung and liver simultaneously. This case demonstrates the importance of obtaining a full drug history, as early identification of the offending agent will improve outcomes.