Epidermoid cysts are benign keratin-filled lesions that commonly occur on the face, neck, and trunk. However, their occurrence in atypical locations such as the hands can present with diagnostic challenges. We present an uncommon case of a 56-year-old man with an idiopathic epidermoid cyst located on the ventral side of the left fourth finger. The 3 × 3 cm lesion persisted for 30 years, causing discomfort, limited mobility, and secondary interdigital fungal infection. The diagnosis was confirmed by excisional biopsy. Surgical excision under wrist-block anesthesia was performed, followed by postoperative care, including wound management, antibiotic therapy, and rehabilitation. This case study elucidates the uncommon location of epidermal inclusion cysts and underscores the significance of histopathological examination. Furthermore, it emphasizes the importance of thoroughly examining the cyst epithelium to ensure complete removal of the capsule and exclude any potential underlying pathology. Early diagnosis and intervention can prevent the development of complications and improve patient outcomes.