The incidence of anal canal cancer (AC) is increased in HIV-positive individuals and is often associated with poor prognosis. High viral load and low CD4 cell count have long been considered relative contraindications for combined modality treatment (CMT) with concurrent chemotherapy and external beam radiation treatment (EBRT) for AC due to severe toxicities. EBRT alone is quite often considered as palliative treatment in nature. We report a case of complete remission (CR) of locally advanced anal canal squamous cell carcinoma (ACSCC) cured after volumetric modulated arc therapy (VMAT) to the primary tumor alone in a 62-year-old male with a 30-year history of AIDS, characterized by an HIV viral load over one million and low CD4 cell count around 100 mm-3. VMAT achieved excellent long-term local control of AC and good quality of life (QoL) of the patient without severe toxicity that requires diverting colostomy.