This study assessed the extent to which clinically measured oral health conditions, adjusted for sociodemographic and oral health behavior determinants, impact adversely on the oral health-related quality of life (OHRQoL) in a sample of Belgian young adults. The null hypothesis was that, among young adults, the oral health conditions would have no impact on their quality of life. The participants were 611 new patients aged 16-32 years seeking consultation at the Saint-Luc University Hospital in Brussels in 2010-2011. The patients (56.0% female) were examined for their oral health conditions and answered a validated questionnaire about sociodemographic and oral health behavior determinants in addition to questions about their OHRQoL. The abridged Oral Health Impact Profile-14 was used to assess the OHRQoL. Interexaminer reliability for caries was 0.86 (95% CI 0.84-0.89, nonweighted κ). The outcome was a high score on the OHRQoL (median split). Hierarchical logistic regression analysis showed that young adults with clinical absolute D1MFS scores between 9 and 16 (OR = 2.14, p = 0.031) and between 17 and 24 (OR = 3.10, p = 0.003) were significantly more likely to report a high impact on their quality of life than those with lower scores. Also, periodontal conditions compromised significantly (OR = 1.79, p = 0.011) the quality of life of young adults. In conclusion, this study identified oral health conditions with a significant adverse effect on the OHRQoL of young adults. However, the prevalence of young adults reporting impacts on at least 1 performance affected fairly often or very often was limited to 18.7% of the sample.