The hypothesis that jugular thrombosis (JT) may cause a mass in the cervical region is usually overlooked. The objective of the present study was to identify the characteristics of neck masses resulting from JT in cancer patients and to analyze the possible reasons for their formation. A retrospective study was conducted on 8 patients with JT affected by 3 types of neoplasia, ie, carcinomas (3 cases), adenocarcinomas (3 cases), and lymphomas (2 cases) located in the breast, digestive apparatus, lymphatic system (2 cases each), lung and an undetermined site (1 case each), diagnosed over the last 12 years. The most frequent symptom of JT was the presence of a mass in the supraclavicular space (62.5% of cases) deeply located on the anterior margin of the sternocleidomastoid muscle and diagnosed by computed tomography and ultrasound. The masses were slightly hardened, with a clearly defined upper limit and an imprecise lower limit and with an irregular surface. The patients also presented with cough, hoarseness, pain during movements, facial edema, and collateral circulation. In one of the patients with a lung cancer, JT symptoms preceded the symptoms of cancer by 2 months. Hypercoagulation, compression, and invasion of a vessel possibly explain the occurrence of JT in these patients.