We report on a 74-year-old man with an acute exacerbation of idiopathic pulmonary fibrosis (IPF) who was successfully treated with prolonged low-dose methylprednisolone, initiated at a loading dose of 2 mg/kg, followed by 2 mg/kg per day for 14 days. The dose was then tapered. The exacerbation observed on the chest radiograph and high-resolution computed tomography was found to have abated after the treatment. This successful case suggests the feasibility of this methylprednisolone treatment protocol for patients with IPF accompanied by accelerated deterioration. Furthermore, this case suggests possible similarities between acute exacerbation of IPF and late acute respiratory distress syndrome, as the same treatment protocol was previously proved to be beneficial for patients with late acute respiratory distress syndrome.