AIM: Inflammatory bowel disease (IBD) diagnosed in adolescence may have adverse effects on educational attainment. The study aims to examine post-secondary educational attainment in patients with IBD and how it is affected by disease severity and comorbid mental health disorders. METHODS: This cohort study used nationwide Danish registries. In a cohort of patients with IBD and matched references, the time to attainment of post-secondary education was examined using Cox regression. In the analysis for disease severity and mental health disorders, the relative risk of attainment of post-secondary education was evaluated using binomial regression. RESULTS: We identified 1136 patients with IBD and 8791 references. Overall, patients with Crohn's disease (CD) or ulcerative colitis (UC) attained a post-secondary education as often as references (CD: hazard ratio (HR) 1.10 (95% confidence interval (CI) 0.99-1.22); UC: HR 0.97 (95% CI 0.88-1.06)). Patients with both severe IBD and mental health disorders had a significantly lower chance of attaining a post-secondary education compared to patients with severe IBD without mental health disorders. CONCLUSIONS: Patients with IBD attained a post-secondary education at the same rate as references. Having both severe IBD and mental health disorder negatively affected post-secondary educational attainment.