Abstract Autoimmune side effects are frequent in patients with cancer treated with immune checkpoint–targeting antibodies, but are rare with cancer vaccines. Here, we present a case report on a patient with metastatic melanoma who developed pulmonary sarcoid–like granulomatosis following repetitive vaccinations with peptides and CpG. Despite multiple metastases, including one lesion in the brain, the patient is alive and well more than 13 years after the diagnosis of metastatic disease. The strongly activated tumor-specific CD8+ T cells showed robust long-term memory and effector functions. It is possible that long-term survival and adverse autoimmune events may become more common for vaccines inducing robust anticancer immune responses as were present in this patient. Cancer Immunol Res; 2(12); 1148–53. ©2014 AACR.