Psoriasis (PSO) is an inflammatory disease that emerges as a dysregulation of the interleukin 23 (IL23)/Th17 axis. There are many biologic alternatives to treat PSO that are administered monthly, every 2 months and every 3?months. Guselkumab (GUS) is a fully human monoclonal antibody, that selectively blocks IL-23 through binding to its p19 subunit. There is scarce evidence on dose optimization of GUS in psoriatic patients. Retrospective, observational case series review which includes patients with moderate-to-severe PSO who switched from ustekinumab to GUS as standard dosing or every 12?weeks, regarding daily clinical practice of every dermatology unit. Clinical and demographic data from patients were included from February 2019 to October 2021. Analyses were performed “as observed” using GraphPad Prism version 8.3.0 for Windows (GraphPad Software, San Diego, CA, USA, www.graphpad.com). A total of 30 patients were included in this study: 20 receiving GUS as standard of care (SC) and 10 receiving an optimized dosing (Q12W) (GUS every 12?weeks without induction). The Q12W group presented greater percentage of comorbidities and was less refractory to previous biologic treatments. After receiving GUS as SC or Q12W, psoriasis area severity index and dermatology life quality index improved dramatically in both groups up to 52?weeks. Survival was 87.2% and 100% for the SC and Q12W, respectively, and there were not safety signals. Our case series of 10 patients receiving GUS every 12?weeks without induction showed a good effectiveness and safety profile accompanied by an excellent treatment survival. However, more studies are needed to provide strong evidence of dosing alternatives different than SC.