BACKGROUND: Prospective data about the acceptance and outcomes of switching from the adalimumab (ADA) reference product (RP) to multiple ADA biosimilars in inflammatory bowel disease (IBD) patients are lacking. OBJECTIVES: To evaluate the acceptance rate of switching from the ADA RP to ADA biosimilars, identify factors associated with non-acceptance, assess persistence at 6 and 12 months, determine reasons for discontinuation, analyze changes in disease activity, and explore patient perceptions at 12 months. DESIGN: A prospective study was conducted at a French tertiary center between July 2020 and September 2021, including consecutive IBD outpatients treated with ADA RP for over 6 weeks. METHODS: Patients were offered a switch to five different ADA biosimilars, with the presence of a trained nurse. Data were collected on acceptance rates, persistence at 6 and 12 months, discontinuation reasons, disease activity, and patient perceptions using a 5-item questionnaire at 12 months. RESULTS: Of the 97 patients included, 91.8% accepted the switch. The only factor linked to non-acceptance was a poor opinion of generic drugs. Persistence with the initial ADA biosimilar was 68.6% at 6 months and 60.4% at 12 months. The overall survival rate without biosimilar discontinuation was 76.7% at 6 months and 71% at 12 months. Injection site pain (24.7%) was the leading cause of discontinuation, and 22 patients switched back to the ADA originator. Clinical remission was maintained in 90.4% of patients at 12 months. Among respondents, 65.8% reported a positive experience with the switch. CONCLUSION: The study demonstrates high acceptance and favorable outcomes for switching to ADA biosimilars in IBD patients, including sustained efficacy and good treatment persistence. These findings suggest that switching to ADA biosimilars is a viable option for IBD patients, with positive results in terms of both clinical effectiveness and patient adherence.