Real-life data on long-term effectiveness and safety of dupilumab in atopic dermatitis patients is limited.To study 52-weeks effectiveness and safety of dupilumab in a prospective multi-center cohort of adult patients with treatment-refractory atopic dermatitis.Patients treated with dupilumab participating in the Dutch BioDay-registry were included. Clinical effectiveness and safety were evaluated.210 atopic dermatitis patients were included. Mean percent change in EASI after 16 weeks was -70.0% (SD 33.2) and further decreased to -76.6% (SD 30.6) by week 52. EASI-75 was achieved by 59.9% at week 16 and 70.3% at week 52. The most reported side effect was conjunctivitis (34%). Limited patients (17 (8.1%))discontinued dupilumab treatment.Due to the lack of a control-group and observational design, factors of bias may have been induced.Treatment with dupilumab resulted in a rapid improvement in clinical outcome measures, and effectiveness further improved during the 52-week follow-up period.