Splenic cysts are extremely rare entities that typically result from prior abdominal trauma, infections, and degenerative diseases. They are divided into two categories: true cysts with epithelial lining, and false pseudocysts without epithelial lining, which is more common than true cysts.We describe here a case of a non-traumatic splenic pseudocyst in a healthy 29-year-old male patient, who presented with left upper quadrant abdominal pain. Physical examination revealed scaphoid abdomen and left hypochondrium fullness. The spleen was uniformly enlarged, smooth, and firm, with mild tenderness. Laboratory testing was normal. An abdominal CT scan showed a huge unilocular non-enhancing cyst occupying the upper part of the spleen, measuring around 16 × 18.5 × 20 cm. The patient was managed with cyst aspiration and partial cystectomy. The histopathological examination findings are consistent with splenic pseudocyst. A one-year follow-up period revealed no complications or recurrence.Spleen cysts are rare in clinical practice, posing challenges in diagnosis and treatment. Surgical options include partial or total splenectomy, cyst aspiration, percutaneous drainage, partial cystectomy, and marsupialization. The choice depends on the cyst's size, splenic coverage, and relation to the hilum. Recently, spleen-preserving approaches have been favored to avoid life-threatening sepsis.Non-traumatic splenic pseudocysts present significant diagnostic dilemmas, requiring histopathological examination for definitive diagnosis. Spleen-preserving management is highly recommended to reduce the risk of life-threatening sepsis.