Psoriasis is associated with comorbidity including obesity, insulin resistance and diabetes mellitus type 2. In obesity, the protein wingless-type MMTV integration site Family, Member 5a (wnt5a) is released from adipose tissue macrophages and was shown to be of importance in the development of insulin resistance. As wnt5a was also shown to be upregulated in psoriatic skin lesions, we investigated whether wnt5a and its counterpart secreted frizzled-related protein 5 are altered in the circulation of lean and obese patients with psoriasis compared with lean and obese healthy volunteers by measuring serum concentrations of both proteins. Our results showed that wnt5a was significantly higher in lean patients with psoriasis (0.096 ng/ml; SD 0.12) compared with lean healthy controls (0.020 ng/ml; SD 0.04; P ≤ 0.01) as well as in obese patients (0.177 ng/ml; SD 0.14) compared with obese healthy controls (0.011 ng/ml; SD 0.03; P ≤ 0.001). Therefore, we suggest that in psoriasis, an increase in wnt5a may contribute to the development of metabolic comorbidity.