The BRAF inhibitor vemurafenib was approved in 2011 for the treatment of inoperable or metastatic melanoma. Vemurafenib therapy is associated with several side effects, such as arthralgia, secondary skin tumors or inflammatory rashes. In particular cutaneous toxicities represent a serious threat to patients' adherence. Here, we present the case of a successful drug desensitization in a patient that presented with a vemurafenib-induced rash. Lymphocyte activation tests failed to detect drug-specific T cells, suggesting that the development of the rash was based upon a nonallergic drug hypersensitivity reaction. A program of slow desensitization was initiated and subsequently, vemurafenib was tolerated at the full effective and recommended dosage.