Objective. The risk of pulmonary embolism is well recognized as showing an increase in oncological patients. We report a case presenting with pulmonary embolism initially, which was then diagnosed with testicular cancer. Clinical Presentation and Intervention. A 25-year-old man was admitted to the emergency department with a complaint of dyspnoea. Thoracic tomography, lung ventilation/perfusion scintigraphy, and an increased D-dimer level revealed pulmonary embolism. For the aetiology of pulmonary embolism, a left orchiectomy was performed and the patient was diagnosed with a germinal cell tumour of the testicle. Conclusion. In this paper, we present a patient for whom pulmonary embolism was the initial presentation, and a germinal cell tumour was diagnosed later during the search for the aetiology.