Background/Objective: To date, no clinical trials have evaluated the therapeutic response among psoriasis patients switching from ustekinumab to secukinumab. The objective of this study was to report our experience of treating psoriasis patients with secukinumab therapy who had ever received ustekinumab previously. Methods: We retrospectively reviewed the therapeutic responses of nine patients with moderate-to-severe psoriasis who attended the clinical trials of first ustekinumab and then secukinumab. Ustekinumab (45 mg) was given at Weeks 0, 4, and 16, and patients were evaluated for safety and efficacy at Weeks 12 and 16. After the end of the ustekinumab treatment period, patients were treated as needed by other modalities. In 2011, eligible patients were recruited again in a Phase 3, double-blind, secukinumab trial (ERASURE). Secukinumab (150 mg or 300 mg) was given at Weeks 0, 1, 2, 3, and 4 and then every 4 weeks. A single evaluator performed all the assessments. Results: Among the nine patients, five patients (55.6%) had at least 75% reduction in the Psoriasis Area Severity Index (PASI75) score response, and four patients (44.4%) had at least 90% reduction in the Psoriasis Area Severity Index (PASI90) score response at Week 12 during secukinumab therapy. Their prior experience during ustekinumab therapy revealed at least PASI75 response in four patients (44.4%) and at least PASI90 response also in four patients (44.4%) at Week 12. Mean absolute PASI change at Week 12 of secukinumab therapy in our patients was -17.47. Conclusion: Biologic switch is effective and valuable. Patients who have ever responded to ustekinumab seem to have a better response to secukinumab. Copyright (C) 2016, Taiwanese Dermatological Association. Published by Elsevier Taiwan LLC.