A 69-year-old man received nintedanib treatment for idiopathic pulmonary fibrosis. After nintedanib treatment was initiated, he had acute abdomen resulting in an emergency right hemicolectomy. He was diagnosed with necrotizing diverticulitis of colon based on pathologic examination of the resected tissue. Intracellular signal transduction inhibitors including nintedanib are known to be associated with such adverse events as hemorrhage, thrombosis, and protracted wound healing. In particular, gastrointestinal (GI) perforation has been frequently reported with bevacizumab, a vascular endothelial growth factor (VEGF) inhibitor. Pretreatment assessment for the patient’s susceptibility to GI adverse effects may be warranted before administration of nintedanib, an inhibitor of the VEGF receptor. We here report a case that developed necrotizing diverticulitis of colon attributed to nintedanib treatment.