Pseudomyogenic hemangioendothelioma (PMH) is a rare, mostly indolent vascular tumor. Extensive cases are treated with amputation as chemotherapy seems to be ineffective. Recently, promising results were published using mammalian target of rapamycin (mTOR) inhibitors in tumors of vascular origin. Here, we present a case of a child with advanced PMH relapsing after surgery and chemotherapy. Sirolimus achieved significant clinical improvement and stabilization of the lesions without any remarkable toxicity. This case contributes to the growing evidence regarding the efficacy of mTOR inhibitors, such as sirolimus, in multifocal PMH.