A 43-year-old Japanese man who had suffered psoriasis vulgaris for eight years visited our hospital. His comorbidities were dyslipidemia, hyperuricemia, and obesity. He received phototherapy for six months, which did not result in improvement. Following treatment with brodalumab, his skin symptoms improved. However, seven months after brodalumab treatment, he received two doses of the mRNA-1273 COVID-19 vaccine, with a one-month interval between doses. One month following the second vaccination, his skin symptoms were exacerbated. He received additional NB-UVB therapy, but his skin symptoms did not improve. Nine months after the addition of NB-UVB therapy, treatment was switched to bimekizumab, and his skin became almost clear. Psoriasis is often associated with comorbidities like metabolic syndrome. Currently, additional COVID-19 vaccination is recommended for high-risk cases such as those with metabolic syndrome. Therefore, it is essential to remain vigilant regarding the potential exacerbation of psoriasis following COVID-19 vaccination even during treatment with highly effective biologic therapy.