The aim of our study was to compare plasma carotenoids (i.e., biomarkers of fruits and vegetables intake) and tocopherols in 29 head and neck squamous cell carcinoma (HNSCC) patients with 51 healthy controls and to explore the possibility whether these plasma antioxidants could be related to outcome among patients. The patients' blood samples were taken at the end of radiotherapy. We observed that plasma lutein, zeaxanthin, alpha-carotene, beta-carotene, lycopene, and total carotenoids were significantly lower in HNSCC patients than controls. Among the patients, 18 died and 11 were still alive during median follow-up of 55 mo for survivors. We found a significant positive association between postradiotherapy plasma carotenoids (lutein, alpha-carotene, and beta-carotene) and progression-free survival in these patients. This study indicates that increasing postradiotherapy plasma carotenoid concentration may reduce risk of premature death or recurrence of tumor in HNSCC patients. Increasing plasma carotenoid concentration should be done by increasing intake of carotenoid-rich fruits and vegetables, as other studies have shown either no or negative effects due to use of carotenoid supplements.