A 79-year-old woman was prescribed bisphosphonates 3 years ago for osteoporosis. At the time of first prescription, she received counselling directions on how to take her medication, which she stringently adhered to. However, she accidentally aspirated an alendronic acid tablet and subsequently developed respiratory tract symptoms. An emergency bronchoscopy was performed. We describe the marked bronchoscopic changes following aspiration of alendronic acid.