We report an exceptional case of primary cutaneous actinomycosis of the hand revealed by microbiological culture and histopathological analysis. Actinomycosis is a chronic bacterial infection caused by Actinomyces spp., anaerobic Gram-positive filamentous bacteria that are commensals of the human mucosa. The cutaneous form is rare, especially on the hand. The diagnosis relies on prolonged anaerobic culture and histological confirmation. We describe the clinical, microbiological, and therapeutic features of this unusual localization and emphasize the importance of bacteriological analysis for diagnosis and management.