Langerhans cell sarcoma (LCS) is a rare proliferation of Langerhans cells with overtly malignant cytologic features and spreads aggressively. LCSs show a multiorgan involvement, including skin, lymph nodes, lung, and bone. The authors report an LCS in a 74-year-old woman that involved the gallbladder and the peritoneal lymph nodes. Imaging revealed a tumor in the gallbladder and the peritoneal lymph nodes. The tumor cells were positive for CD1a, S-100 protein, and Langerin (CD207). Although the ultrastructural analysis failed to demonstrate any Birbeck granules, the histomorphological and immunohistochemical findings supported the diagnosis of LCS. After surgical resection, she showed no recurrent or metastatic signs for 8 months without any other adjuvant therapy. This is the first case of LCS involving the gallbladder and the peritoneal lymph nodes. This report also includes a review of the literature concerning this rare disease.