Objectives The objective of this study was to describe oral health literacy and its association with periodontal health status. Methods A population of young adults, enlisted personnel, at a military police force at Escola da Guarda (EG - GNR) in Portalegre, Portugal, participated in this crosssectional study. Information on sociodemographic, dental and oral health literacy was collected. Oral health literacy was assessed using OHLI (Oral Health Literacy Instrument). Clinical periodontal examinations were performed, and data was obtained for oral hygiene status and severity of gingival inflammation. Results A total of 274 participants enrolled and completed the study. Most participants (54.7 percent) had an adequate oral health literacy level. For 38 percent the level of literacy was marginal and, 7.3 percent had an inadequate level of oral health literacy. There is an association between education and oral health literacy (P<0.001). Female participants had more general oral health knowledge than males (P=0.034). Participants with the 12th grade or less have statistically significant less general oral health knowledge than participants with a bachelor’s degree (P<0.001). Dental plaque index was lower for participants with higher attendance of dental appointments (P=0.002) and adequate oral health literacy (P = 0.009). Conclusions Oral health literacy, education and frequency of dental appointments were associated. General oral knowledge is worst for males and people with lower education levels. Oral hygiene status is better for participants with adequate oral health literacy and a higher number of dental appointments.info:eu-repo/semantics/publishedVersio