Background: Elafin is barely detectable in normal skin and is strongly expressed in inflamed skin. It is highly expressed in epidermis, sputum, and urine of psoriatic patients but is not specific for psoriasis. Objective: To estimate the serum level of elafin in psoriasis cases and its correlation with the severity of psoriasis. Patients and methods: This was a case-control study carried out on 45 patients with different clinical types of psoriasis who were newly diagnosed or stopped systemic treatment for at least 3 months before the study. They were recruited from the Outpatient Clinic of Dermatology Department, Mansoura University Hospital. In addition 45 normal healthy subjects with matched age and sex were selected to act as a control group. Results: The mean onset, duration and psoriasis area severity index (PASI) were 37 ± 9.43, 8.37 ± 8.07 and 23.28 ± 14.53 respectively.     Psoriasis group was associated with a significant increase in serum elafin level compared to the control group. Cases with severe psoriasis demonstrated the highest serum elafin level followed by moderate psoriasis and lastly mild psoriasis. ESR, CRP and elafin could be used as reliable biomarkers in terms of the differentiation among psoriasis and the control group with high accuracy, sensitivity and specificity. Elafin level was demonstrated to be significantly correlated with PASI, ESR and CRP. Conclusion: Elafin level demonstrated significant elevation among psoriatic cases and correlated positively with the disease severity (as revealed by PASI score). Thus, it could be used as a promising predictor for psoriasis diagnosis, which could impact the therapeutic lines in the future.