Résumé : INTRODUCTION: The overall survival rate for patients with head and neck squamous cell carcinoma remains disappointingly static despite improved locoregional control. This has been attributed to the development of distant metastases and second primary malignancies in these patients, a large proportion of which occur in the thorax. The goal of this study is to determine the incidence of newly thoracic malignancies diagnosed initially and during the follow-up in head and neck patients by chest computed tomography. METHODS: We retrospectively analysed the incidence of thoracic malignancies in 77 patients presented newly diagnosed cancer of the head and neck. RESULT: 15/77 patients were found to have thoracic malignancies. In 10/77 patients (14%) the diagnosis was made at the same time that the initial head and neck cancer In 5/77 patients, the thoracic malignancies were diagnosed during the follow-up. In 3 of the 5 cases, the pulmonary lesion was diagnosed in patients with local recurrent tumours. The primary site or the stage had an effect on the incidence of simultaneous thoracic malignancies. CONCLUSION: The presence of distant metastases and second primary malignancies has major implications in the management and prognosis of patients presenting with head and neck carcinoma. We recommend a CT scanning of the thorax in the staging of patients presenting with head and neck cancer but also in the follow-up, particularly in patients with an advanced pharyngolaryngeal cancer.