A number of anticancer drugs, especially molecularly-targeted drugs, have been developed every year. Drug-induced interstitial lung disease(DILD)is a common adverse event associated with molecularly-targeted drugs, and it is therefore important to obtain information about the DILD risks of each drug. Recently, all-case surveillance of new drugs have been carried out frequently as post-marketing surveillance. This allows one to understand the accurate status of DILD, such as its incidence rate and prognosis. The diagnosis of DILD is often difficult because there is no specific diagnostic approach. It is necessary to distinguish DILD from various other diseases including infectious disease, cancer progression, congestive heart failure, etc. Among those, respiratory infection is an important disease in the differential diagnosis of DILD, because patients receiving anticancer drugs are likely to be susceptible to infection. As for the treatment of DILD, the general rule is the discontinuation of the offending drug, and if necessary, the administration of corticosteroid is indicated. However, an exceptional treatment is required for DILD caused by mTOR inhibitor, for which we must take account of the adequate management.