Intraoperative pulmonary thromboembolism (PTE) is rare, but is nevertheless one of the important causes of morbidity and mortality in patient undergoing surgery. However, The detection of PTE is difficult because it's clinical symptoms and signs are nonspecific during surgery, and specialized diagnostic tools are not readily available in the operating room. We report a case of PTE due to cancer emboli with thrombi encountered during a nephrectomy in patient with renal cell cancer, and demonstrate that one-lung ventilation can aid in the diagnosis of massive PTE when the evaluation is suspected.