Development of molecular targeted drugs has achieved remarkable improvement of systemic cancer therapy. Recently, the several molecular targeted drugs have become available which associated with the status of responsible genes for hereditary cancer syndrome. These drugs would allow to establish specific strategy for hereditary cancer syndrome or sporadic cancers with similar biological phenotype with hereditary cancer. Genetic tests for the diagnosis of hereditary cancer syndrome will have the meaning of biomarker for predicting the efficacy of these molecular targeted drugs. This review summarized the molecular targeted drugs including immune checkpoint inhibitors with potential effects for hereditary cancer syndrome, such as anti-PD-1 antibody for Lynch syndrome, PARP inhibitor for hereditary breast and ovarian cancer syndrome, multi-kinase inhibitor for multiple endocrine neoplasia type 2.