Results: we included 313 patients in the study, 62.3% with CD, 69.7% under IFX and 30.3% under VDZ. 60 patients (19.2%) were under 25 years at the start of the biologic, 184 patients (58.8%) were between ages 25 and 54 years, and 69 (22%) were >55 years.Patients with >55 years at the start of treatment presented lower rates of clinical remission (65.2% vs 81.7%, P= 0.047) and fecal calprotectin remission (33.3% vs 66.7%, P<0.001), higher need for hospitalization (23.2% vs 6.7%, P= 0.014), emergency care assistance (11.6% vs 1.7%, P= 0.037) and of a compound outcome including any unfavorable outcome (82.6% vs 56.7%, P= 0.002) compared to patients <25 years. Patients with >55 years also presented lower rates of fecal calprotectin remission compared to patients with 25-54 years (66.3%, P= 0.013).In multivariate analysis including age at diagnosis, disease subtype, previous biologic exposure, type of biologic and gender, age at the start of biologic >55 years was independently associated with a higher likelihood of reaching any unfavorable outcome – OR 2.741 95%CI 1.361-5.519, P= 0.005.Conclusion:our findings suggest that older age at the start of biologic may result in inferior treatment outcomes.