We report a 74‐year‐old Japanese man with triple extramammary Paget's disease; the genital and both of the axillar regions were simultaneously involved. Literature review revealed that 27 cases of triple extramammary Paget's disease have been reported in Japan, but there are no reports of triple extramammary Paget's disease from countries other than Japan, although 2 cases of double extramammary Paget's disease are reported. In all 28 cases, including our case, the genital lesion preceded the axillary lesions. All cases except one were male and only the exceptional female case was reported to have an the invasive tumor in the dermis. We speculate that extramammary Paget's disease may appear multi‐centrically.