Background: Psoriasis is a chronic immune-mediated skin diseasewith a genetic predisposition. Prolactin may contribute to psoriasispathogenesis. However, there has been a debate over the serumlevel of prolactin in psoriatic patients. The aim of this study was todescribe the role of serum prolactin in the pathogenesis of psoriasisMethod: The serum prolactin level was measured in 45 patientswith psoriasis and in 45 sex- and age-matched healthy individualsusing radioimmunoassay.Result: The mean serum prolactin concentration was not differentbetween psoriatic patients and healthy controls (320 ± 179.38 vs.318.18 ± 191.78 mIU/L, respectively P = 0.95). There was no sexandage-related differences in serum prolactin between the twostudy groups. Hyperprolactinemia (serum prolactin >324 mIU/Lin men, and >496 mIU/L for women) was observed in 11 patientswith psoriasis and 12 healthy subjects, which showed no significantdifference between the two groups (P = 0.81). The serum prolactinwas not significantly correlated with the duration of the disease(r = -0.18, P = 0.24) or the PASI score (r = 0.10, P = 0.50).Conclusion: The possible role of pituitary-produced circulatingprolactin in the disease process needs further investigations.