Background: Osteoporosis and periodontitis are both considered global health issues that threaten postmenopausal women and the older population. However, the correlation between osteoporosis and periodontitis is still unclear. Methods: Using a nationwide Taiwanese population‐based database, data from patients with osteoporosis (2003 to 2005; n = 2,527) and 7,575 individuals who were matched to each patient by age and sex were analyzed. All participants were tracked for 5 years from the date of enrollment to observe the percentage of patients who developed periodontitis. Cox proportional hazard regressions were performed to evaluate 5‐year periodontitis‐free survival rates. Results: Among the total sample, 3,060 individuals were diagnosed with periodontitis during the 5‐year follow‐up period: 792 in the study cohort and 2,268 in the comparison cohort. The adjusted hazard ratio for periodontitis in patients with osteoporosis compared with individuals without osteoporosis during the 5‐year follow‐up was 1.14 (95% confidence interval = 1.05 to 1.24, P <0.01). Conclusion: This population‐based study indicated that patients with osteoporosis may have an increased risk of periodontitis.