Psoriasis affects mainly skin, nails and joint and is characterized by the presence of sharply demarcated, red plaques with adherent silvery white scales and a tendency for symmetrical distribution over the body. Psoriasis can be provoked by external and internal triggers, including mild trauma, sunburn, infections, systemic drugs and stress. There is a strong positive association between psoriasis and known risk factors including central obesity, insulin resistance and dyslipidemia. Sirt-1 is a NAD+-dependent deacetylase involved in the regulation of a myriad of cellular processes including mitochondrial biogenesis, genomic stability, cellular senescence and apoptosisAim: The aim of this study was to assess serum levels of sirt-1 in psoriasis patients and correlate their levels with the severity of the disease.. Method: This present study included: Patient group (group 1) included 25 psoriasis patients. In addition, 15 apparently healthy, age and sex matched individuals included as a control group (Group 2). All were investigated for serum sirt 1 level and compared. Serum Sirt 1 were estimated using commercially available ELISA kits. Conclusion: From the results of present study, it is concluded that sirt 1levels are lower in psoriasis patients not corrospnding to the disease severity.