BACKGROUND: Early advanced inflammatory bowel disease (IBD) therapy is emphasised to prevent disease progression and restore quality of life. AIMS: To evaluate the potential advantages of early versus late anti-tumour necrosis factor (TNF) therapy in patients with IBD. METHODS: This retrospective study included patients with newly diagnosed IBD (2004-2018) who received anti-TNF therapy and had at least 1 year of follow-up. Patients were categorised as early or late users based on a 2-year post-diagnosis cut-off for first anti-TNF exposure. Outcomes included IBD-related surgeries, hospitalizations, emergency department (ED) visits, and drug persistence. Subgroup analysis examined concurrent immunomodulator use, and sensitivity analyses were employed 6 months or 1 year post-diagnosis cut-offs. RESULTS: Among 8105 patients with ulcerative colitis (UC) and 8465 with Crohn's disease (CD), distinct outcomes emerged. Early anti-TNF users with UC had significantly higher hospitalization (hazard ratio [HR] 1.34, 95% confidence interval [CI] 0.91-1.96) and ED visit rates (HR 1.30, 95% CI 1.16-1.46) compared with late users. In CD, early users showed a non-significant trend toward fewer event rates. Drug persistence was longer among late users for both UC and CD. In UC, combining immunomodulators with early anti-TNF increased hospitalization and ED visits but not in CD. Sensitivity analyses confirmed the primary findings. CONCLUSIONS: While early anti-TNF use was associated with differential outcomes in CD, the relationship between treatment timing and clinical course diverged in UC, challenging the assumption that early intervention is universally advantageous across IBD subtypes. These findings underscore the need for further research to identify patient subgroups that might benefit most from early intervention.