A 67-year-old woman presented with a right inguinal mass in May 2006. CT scan showed lymph node involvement from the right inguinal to the common iliac and (18)F-FDG-PET revealed uptake in those areas. Biopsy results indicated Langerhans cell sarcoma (LCS). Interestingly, tumor cells expressed a high MIB1 index of 30%. We administered doxorubicin, ifosfamide, and mesna (AIM) chemotherapy, which were reported to effectively treat soft tissue sarcoma. After 5 courses of AIM therapy and involved-field radiation for residual diseases and a relapsed lesion on her right cervical node, she has remained in complete remission for more than 4 years. LCS is an intractable malignant disease and the optimal therapeutic strategy remains unclear. The AIM regimen combined with radiation therapy may be an effective treatment option for this disease.