About 13% of patients treated for a pharyngeal cancer suffer from a second primary cancer. Excessive consumptions of tobacco and/or alcohol are recognized as risk factors of second primary cancers in these patients. Epidemiologic studies suggest that antioxidant vitamins could have a protective effect on the occurrence of second primary cancers; however, this hypothesis should be confirmed by randomized clinical trials. A better knowledge of the risk factors of second primary cancers in patients with a pharyngeal cancer could help reducing the occurrence of second primary cancers and improving the follow-up of these patients.