Many anti-cancer drugs cause infertility. Regional delivery of these agents is a potential method to avoid this problem. We investigated the protective effect of normothermic testicular circulatory arrest on gonadal toxicity during doxorubicin administration in the Sprague-Dawley rat. Four groups of eight rats each were used. Animals in group 1 received no treatment. Rats in group 2 were anesthetized and received a bolus of intravenous doxorubicin (6 mg/kg). In groups 3 and 4, normothermic circulatory isolation of the left testis was induced by cross-clamping of the spermatic cord and gubernaculum immediately before doxorubicin administration. This was maintained for 15 min after doxorubicin administration in group 3 and for 45 min in group 4. Cessation and return of testicular blood flow were confirmed by Doppler. On Day 56, all rats were killed and necropsied. Testicular toxicity was evaluated qualitatively by histology and quantitatively by measurement of testicular weight, sperm count, repopulation index, and epididymal index. The results indicated that 15 min of testicular circulatory isolation mitigated testicular toxicity to a small extent and that 45 min of circulatory isolation provided moderate protection against doxorubicin-induced testicular toxicity.