BACKGROUND: Incidence of oral tongue squamous cell carcinoma (OTSCC) is increasing, especially in young adults, despite decreasing tobacco and alcohol consumption. METHODS: This multicentric retrospective study of 185 young adults with OTSCC (median follow-up 43 months), investigated risk factors, tumour characteristics and oncological outcomes according to the smoking status. RESULTS: Overall, 38% of patients were smokers (S). Non-smokers (NS) were significantly younger than S. Sex ratios were 1.1 for N and 1.8 for S. NS patients were less frequently cannabis or alcohol users than S, but were more likely to have a history of leukoplakia. Second primaries were observed in NS (4.4%) and in S (12.7%). Despite more frequent local relapse in NS (p = 0.018), there was no difference in diagnostic stage and overall survival between groups. CONCLUSION: OTSCC affects differently young S and NS patients suggesting the existence of a specific clinical entity of OTSCC in non-smoking young adults.