BACKGROUND: Atopic dermatitis (AD) might delay puberty, but research is lacking. OBJECTIVE: To investigate the association between AD and puberty. METHODS: A subcohort within the Danish National Birth Cohort includes children born between 2000 and 2003, with mothers reporting doctor-diagnosed AD at 6 months, 18 months, and 7 years old. The National Patient Registry identified hospital-diagnosed AD. From 11 years, the children give half-yearly information on pubertal development. We estimated the mean age difference in months at attaining Tanner stages 1 to 5 and the development of axillary hair, acne, first ejaculation, voice break, and age at menarche, using an interval-censored regression model. RESULTS: In total, 15,534 children participated, 21.5% had self-reported doctor-diagnosed AD and 0.7% had hospital-diagnosed AD. For girls with self-reported doctor-diagnosed AD, the average age difference at reaching all pubertal milestones was 0.0 months (95% confidence interval [CI]: -0.8; 0.8), and for hospital-diagnosed AD, it was -0.3 months (95% CI: -5.4; 4.8). For boys, the average age difference was 0.1 months (95% CI: -0.6; 0.9) and -0.3 months (95% CI: -3.6; 3.0), respectively. LIMITATIONS: No information on treatment was available. Missing data on covariates (<5%) were not addressed. CONCLUSION: No association was found between AD and puberty in either girls or boys.