The combination of oxaliplatin, 5-fluorouracil and leucovorin (FOLFOX) has recently been shown to be beneficial in advanced colorectal and gastric cancers. The side effects of this regimen include neutropenia, diarrhea and neurosensory toxicity. However, case reports on the pulmonary toxicities of this regimen are very limited. Especially, the development of pulmonary fibrosis has never been cited in the literature. Herein is reported the case of a patient treated with oxaliplatin, 5-fluorouracil and leucovorin combination chemotherapy in whom pulmonary fibrosis developed, but which improved after steroid pulse therapy.