The attention is given to Nivolumab induced interstitial lung disease (refered to as ILD). In some cases, even deaths have been reported. The standard protocol is that once a sign of ILD is seen, stop Nivolumab and switch to corticosteriod, but there is no enough data to back up this protocol. Among the non-small cell lung cancer patients who were given Nivolumab between January 2016 and December 2016, there was one patient who experienced grade 2 ILD and another patient with grade 3 ILD. Both of these patients’ symptoms of ILD were mostly contained after given 1g/day of Methyprednisolone Soduim Succinate for 3 days, then oral prednisolones with gradually decreasing the dosage of it. Regarding the manifestation of ILD, it varied and it was somewhere bewteen second to 12th doses of Nivolumab with the median of 8th doses. This study was able to confirm the effective response to corticosteriod for grade 2 or higher cases of ILD.