Pyoderma gangrenosum is an ulcerative skin disorder showing characteristic non-infectious ulcers and affects the lower extremities in approximately 70% of cases. Pyoderma gangrenosum is commonly associated with systemic diseases such as inflammatory bowel disease, rheumatoid arthritis and hematological malignancies. Herein, we report two cases of Japanese patients diagnosed with genital pyoderma gangrenosum. Case 1 was a 74-year-old woman without associated systemic complications, whose skin lesion resembled a squamous cell carcinoma and was limited to the vulva. Case 2 is an 89-year-old man, who suffered from myelodysplastic syndrome and acute myeloid leukemia, and presented with penile and leg ulcers mimicking pressure sores. Both cases responded well to systemic steroids. We review 13 genital pyoderma gangrenosum cases (76.9% male; aged 30–89 years) from 1996 to 2012 in Japan, including 11 previously reported cases and the present study's two cases. Four of the 13 genital pyoderma gangrenosum cases had associated systemic diseases and their skin lesions spread to the extragenital areas. Eight of the remaining nine genitalia-localized pyoderma gangrenosum cases had no associated systemic diseases. In conclusion, genital pyoderma gangrenosum is rare and may be misdiagnosed. It should therefore be considered in cases of refractory genital ulcers. In addition, genitalia-localized pyoderma gangrenosum tends to be without systemic complications.