Background <p>Leukocyte telomere length (LTL) has been implicated in various health outcomes, but its association with attachment loss in periodontal health remains underexplored.</p> Methods <p>A total of 2521 US adults (Age: 61–85; Men: 50.5%) from the National Health and Nutrition Examination Survey (1999–2002) were included in this cross-sectional study. Baseline demographics were obtained from the questionaries, and LTL was determined using a polymerase chain reaction, and periodontal attachment loss was defined according to a professional physical examination. Multivariable regression analyses were conducted to assess the association between LTL, treated as a categorical and continuous variable, and periodontal attachment loss. The sensitivity analysis was verified by subgroup analyse, where interaction terms were used to examine the heterogeneity in associations across different subgroups.</p> Results <p>Compared to the lowest quartile, the highest LTL quartile exhibited a significant positive association with periodontal attachment loss in the fully-adjusted model (β: 1.54 to 1.71, <i>P</i> &lt; 0.05). When LTL was treated as a continuous variable, a positive association persisted in the fully-adjusted model (β: 2.22 to 3.24, <i>P</i> &lt; 0.05). Subgroup analyses revealed a consistent positive association between LTL and periodontal attachment loss.</p> Conclusions <p>This study provides evidence of a positive association between leukocyte telomere length and attachment loss in periodontal health. Our results suggested that LTL may serve as a potential biomarker for periodontal health, emphasizing the importance of considering telomere length in understanding and managing periodontal conditions.</p>