Guselkumab is approved by the Food and Drug Administration for the treatment of moderate-to-severe plaque psoriasis. However, characteristics of patients initiating guselkumab in a real-world setting are not well characterized. The present study described baseline characteristics of patients with psoriasis initiating guselkumab in the first year after approval using data from the Symphony Health Claims database. Adult patients with psoriasis with ≥1 claim for guselkumab between 7/13/2017 and 7/2/2018 were included. The index date was defined as the date of the first pharmacy claim for guselkumab. Outcomes of interest included demographics, frequency of prior biologic and non-biologic psoriasis treatments, and frequency of diagnoses or procedures during the year before guselkumab initiation (baseline period). A total of 1,520 patients were included. Mean age was 51.2 (SD 13.4) years and 53.7% of patients were female. During the baseline period, 63.9% of patients had ≥1 biologic drug claim and 66.9% were prescribed topical corticosteroids/combinations. The most common non-psoriasis diagnoses among patients with ≥1 medical claim were hypertension (25.1%), type 2 diabetes (13.4%), and hyperlipidemia (13.4%). The most common procedures reflected routine medical care. These findings describing the baseline characteristics of patients initiating guselkumab provide insights regarding variables that may impact observed treatment outcomes and may ultimately help with treatment decision making. J Drugs Dermatol. 2021;20(10):1127-1131. doi:10.36849/JDD.6024.