Pulmonary embolism (PE) is a prominent cause of morbidity and mortality in surgical patients. Here, we report two cases of PE following head and neck surgery: (1) in case 1, the patient underwent endoscopic sinus surgery (ESS), and (2) in case 2, the patient was suspected PE after resection of the parotid gland and radical neck dissection. Prophylactic compression devices were used during the operation in both cases. In case 1, PE was diagnosed 3 days following surgery after the patient complained of dyspnea while walking. PE was successfully treated by intravenous administration of heparin. In case 2, PE was strongly suspected 13 days following surgery after the patient experienced syncope and chest pain and exhibited abnormal findings on a cardiac echogram. This patient died 18 h after the onset of cardiac symptoms. Despite prophylactic measures taken during surgery, the prognosis was poor for this patient due to numerous high-risk factors (e.g., advanced age, obesity, prolonged immobilization). Although the incidence of postoperative PE in our department during the last 7 years is very low (0.04%), the frequency of postoperative PE in Japan has steadily increased in recent years. PE still is one of the most significant complications leading to morbidity and mortality following surgery. Given the gaining prominence of PE, we conclude that otolaryngologists including those in Japan should be reminded of high-risk factors associated with PE and be made aware of prophylactic treatments newly aimed at reducing the frequency of PE.