We report here a case of dermal cutaneous alternariosis in a 69-year-old man with X-linked chronic granulomatous disease (CGD). The lesion on the back of the right hand spread and became indurated, even though oral itraconazole 100 mg daily for 12 weeks was administered. After 28 weeks of treatment with oral fluconazole at 200 mg daily, the lesion disappeared and left only slight pigmentation. Alternaria species are common saprophytes that are not usually pathogenic in humans. However, there are some reports of cutaneous alternariosis in immunocompromised patients. To our knowledge, this is the first case of cutaneous alternariosis in CGD and the response to fluconazole, a drug not usually used for this mycosis.