Objective: Estimate the direct medical costs of treating psoriatic arthritis (PsA), including in-patient and out-patient treatment costs. Methods: The retrospective study follows a prevalence-based approach, collecting all patients with PsA undergoing treatment at the National Hospital of Dermatology and Venereology from July 1, 2021 to December 31, 2022. Data collected included demographic characteristics and costs covered by the social health insurance (SHI). Results: Among the 74 patients included in the study, 64 patients received outpatient treatment, eight patients received both outpatient and inpatient treatment, and two patients received inpatient treatment only. The average monthly cost of outpatient treatment was 1.7 ± 2.2 million VND, with an average of 0.7 ± 0.3 outpatient visits per month. The average cost for an inpatient treatment session was 6.8 ± 6.2 million VND, with an average duration of 16.2 ± 20.9 days. Conclusions: We have analyzed the economic burden of PsA from SHI perspective and shown medication costs accounted for the highest proportion of expenses in all cost categories.