An 84-year-old woman was admitted to the emergency room with hemoptysis consisting of relevant amounts of fresh blood. She was treated with phenprocoumon for 11 years following mechanical aortic valve replacement without any complication. Laboratory results revealed phenprocoumon over dosage with international normalized ratio over 6. Chest radiograph showed diffuse alveolar infiltrates conformable to diffuse alveolar hemorrhage. Besides the pulmonary complication no other bleeding occurred. She needed noninvasive ventilatory support for 24 h to cope with the symptoms of an acute respiratory failure. After substitution of vitamin K dependent blood clot factors resulting in a normalized coagulation hemoptysis which persisted for another 3 days followed by a slow recovery. Other causes of diffuse alveolar hemorrhage were excluded in our patient. This case report presents a rare case with diffuse alveolar hemorrhage as the leading and sole symptom due to phenprocoumon overdose.