Concurrent chemoradiotherapy with 5-fluorouracil plus mitomycin C has been established as a standard therapy for non-metastatic anal squamous cell carcinoma in the West. However, there have been few reports of chemoradiotherapy for anal squamous cell carcinoma in Japan. We retrospectively investigated seven consecutive anal squamous cell carcinoma patients who were treated with concurrent chemoradiotherapy consisting of 5-fluorouracil plus mitomycin C with a total irradiation of 59.4 Gy. The patients consisted of two males and five females. Clinical stages II/IIIA/IIIB accounted for four, one and two patients, respectively. Full-dose irradiation was completed in all patients. Median relative dose intensities of 5-fluorouracil and mitomycin C were both 99%. All patients achieved complete response. At a median follow-up of 37.5 months, one patient experienced local recurrence. The most common grade 3/4 acute toxicities were dermatitis in 100% and anal pain in 71%. There was no treatment-related death. Concurrent chemoradiotherapy appears to be tolerable and effective in Japanese patients with anal squamous cell carcinoma.