Psoriasis considered a chronic inflammatory skin disease characterized by spontaneous remissions and exacerbations. The lesions are characterized by circumscribed, dry, erythematous plaques of various sizes covered by silvery white scales.  Periostin gene (POSTN) in human is located in the long arm of chromosome 13 (13q13.3) and spans approximately 36 kb, It has 23 exons and encodes for a protein of 836 amino acids with a molecular weight of 93 kD, it was renamed periostin due to itˈs localized expression in the periosteum and the periodontal ligament.The aim of this study was to reveal the association between periostin (rs3829365) gene polymorphism and psoriasis susceptibility. Blood samples were taken from psoriasis patients and control group for genotyping of Periostin gene using PCR. Regarding periostin gene polymorphism, CG  and GG genotypes showed higher distributions among psoriasis patients than control and total polymorphism showed higher distributions when compared to CC genotype frequency and G allele carry a risk factor for psoriasis susceptibility.Periostin genpolymorphism(rs3829365)  genotypes frequencies CG,GG and(CG+GG) and G allele might play a role in psoriasis pathogenesis.