Our previous study showed that cysteine sulfinate decarboxylase (CSD) is expressed in the testis, epididymis, and ductus deferens. However, the expression of CSD and taurine concentration in the male accessory sex glands remain unknown. Therefore, we conducted immunohistochemical analysis, semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), and western blotting in order to examine CSD expression in the seminal vesicle; bulbourethral gland; and prostate gland, including the dorsolateral prostate, ventral prostate, and anterior prostate. We also analyzed the tissue taurine concentration by using high-performance liquid chromatography (HPLC). Immunohistochemical analysis revealed that CSD is expressed in the tall columnar cells of the seminal vesicle, the glandular epithelium of the bulbourethral gland, and the epithelial cells of the intermediate segments of prostate gland. The taurine concentrations in the dorsolateral prostate, ventral prostate, and anterior prostate; seminal vesicle; and bulbourethral gland in terms of micromoles per gram wet weight were 6.09+/-0.67, 6.62+/-0.43, 4.14+/-0.05, 12.55+/-1.03, and 7.50+/-0.64, respectively; these values are similar to the relative expression levels of the CSD protein. These results demonstrate that CSD is expressed in the accessory sex glands of mice, and they confirm our hypothesis that male accessory sex glands are able to synthesize taurine through the CSD pathway.