Nonbacterial thrombotic endocarditis (NBTE) is a well-known complication of hypercoagulable states, particularly in patients with malignancies. Its complications comprise thrombembolism rather than valvular dysfunction. We present a case of a 71-year-old man treated for colonic carcinoma, who died 1 month after tumor resection with clinical signs of respiratory failure. Ante mortem, there was no suspicion of cardiac disease. The autopsy revealed NBTE affecting all four cardiac valves simultaneously, as well as multiple systemic and pulmonary thrombemboli. Microscopically, neither microorganisms nor inflammation were found in the thrombi and/or valve tissues. To the best of our knowledge, this is the fourth case of quadri-valvular NBTE reported in the English-written literature so far.