集尿系統尿液外滲後所引起的肋膜積液，在臨床上屬於罕見。本文報告兩例集尿系統尿液外滲後所以發的肋膜積液；一例為輸尿管原因不明性破裂，另一例為經皮穿腎手術後。兩例經由適當處理後，肋膜積液均自動消失。我們在文中特就文獻回顧針對此種非尋常肋膜積液的發生機轉，診斷方式及處理方法，加以討論。同時我們也要提醒臨床醫師，當發現有尿液外滲至後腹腔後，若是尿路阻塞仍然存在則有可能會發生肋膜積液。

Pleural effusion associated with retroperitoneal urinary leakage is unusual. This uncommon finding may be owing to urinary tract obstruction, trauma. Retroperitoneal inflammatory or malignant processes, failed nephrostomy or kidney biopsy. We describe two cases of pleural effusion with extravasation of urinary system; one who had spon-taneous ureteral rupture and the other who had a history of failed percutaneous nephrolithotomy. In boht of the cases, the pleural effusion resolves following adequate urinary diversion.