Introduction: Pancreatic melanoma is an extremely rare condition, especially those of unknown primary (MUP), accounting for about 2% of visceral involvement in melanomas. Case Report: A 43-year-old man with a history of hypertension sought medical attention due to severe epigastric pain radiating to the back, nausea, postprandial fullness, and urinary changes. Laboratory tests revealed elevated ferritin, erythrocyte sedimentation rate, blood glucose, C-reactive protein, and mild leukocytosis. Imaging studies identified a cystic lesion in the head of the pancreas, which had significantly increased in size from 11 mm in 2013 to 51x59x37 mm at the current presentation. Endoscopic ultrasound (EUS) revealed a well-defined, hypoechoic, and homogeneous solid lesion, located in head to pancreas body transition, and a fine-needle biopsy guided by EUS (EUS-FNB) was performed. Histopathological and immunohistochemical analysis confirmed the diagnosis of small cells melanoma with neuroendocrine differentiation. Dermatological evaluation and PET-CT did not identify any skin lesions, with uptake limited to the pancreas. Laparoscopy revealed hepatic and peritoneal metastases, confirming metastatic melanoma. Discussion: This case highlights the diagnostic challenges of pancreatic melanoma, particularly in the absence of skin lesions, and emphasizes the importance of histopathological and immunohistochemical analysis via EUS for an accurate diagnosis. The rarity of primary pancreatic melanoma and the lack of definitive diagnostic criteria necessitate further research to better understand its pathogenesis and optimal management.