Bilothorax is a rare cause of an exudative pleural effusion. The diagnosis is confirmed by a pleural fluid to serum bilirubin ratio of greater than 1. Typically, bilothorax presents as a right-sided effusion due to its proximity to the liver and biliary system. Herein, we present a case of isolated left-sided bilothorax in a 43-year-old female admitted with sickle cell crisis. Only one other case of isolated spontaneous left-sided bilothorax has been described in the literature. A thoracentesis performed on admission demonstrated greenish fluid and bilothorax was suspected, with a pleural fluid to serum bilirubin ratio greater than 1 confirming the diagnosis. A magnetic resonance cholangiopancreatography (MRCP) showed an abnormal 90-degree acute angulation in the mid-to-distal common bile duct with proximal common bile duct and intrahepatic bile ducts dilation. This was further confirmed with an endoscopic retrograde cholangiopancreatography (ERCP), which did not reveal any extravasation of contrast into the left pleural space. Ultimately, despite the use of various modalities, no definitive cause of bilothorax was identified. Postthoracentesis imaging revealed evidence of fibrothorax, a direct and permanent complication of bilothorax. The presence of an isolated left-sided bilothorax, along with the lack of a confirmed etiology, makes this case unique.