Psoriasis is an immune-mediated disease where the IL-23/Th17 axis as well as TNF comprise main targets of biological therapy. Immune profiling has so far not been embraced as a clinical tool. We aimed to investigate relationships between individual serum cytokine levels in 40 psoriasis patients before and after receiving biological therapy and Psoriasis Area and Severity Index (PASI) and Dermatological Life Quality Index (DLQI). Serum concentration of 25 cytokines was determined by Luminex technology. Mean PASI and DLQI decreased by 71% and 65%, respectively. Increase of IL-2 positively correlated with improvement of PASI and DLQI. Moreover, increase of IL-5, IL-10, IL-12, IL-22 and GM-CSF correlated with treatment effect. Notably, logistic regression revealed four times higher risk of having severe psoriasis when IL-17A increased by 1 pg/mL (OR: 4.06, P < 0.05). Selected serum cytokines might constitute useful biomarkers for monitoring disease activity and optimizing therapeutic strategies in psoriasis patients.