Background: Polymorphisms of genes including tumor necrosis factor alpha (TNF-α) and Tumor necrosis factor receptor super family 1B (TNFRSF1B) may influence susceptibility to psoriasis as well as patients' biological responses. Aim of the study: To demonstrate the potential roles of TNF-α and TNFR1B, genes polymorphism {TNF-α -308 (G/A) and TNFR1B rs1061622 (T/C)} in susceptibility to psoriasis, elucidating their possible influence on patients' biological drug response and serum level. Subjects and methods: One hundred psoriatic patients and 100 apparently healthy individuals as a controls were included in this study. Restriction Fragment Length Polymorphism-Polymerase Chain Reaction (RFLP-PCR) was performed to evaluate different TNF-α and TNFR1B genes polymorphism. TNF-α and TNFR1B serum levels were assessed by enzyme linked immune sorbent assay. Results: Comparison between overall patients and controls revealed a higher serum level of TNF-α in patients than the controls with a highly significant difference (P<0.001). The risk of psoriasis was observed among people who had TNF-α-308 AA or GA genotypes, namely A allele-containing genotypes. Regarding the response to treatment it was revealed that the mutant homozygous genotype AA with higher frequency in non-responder (85.7%). The risk of non-response to biological drug was higher in people carrying AA genotype than in people carrying GG or GA genotypes. Concerning to serum level of tumor necrosis factor receptor super family member 1B (TNFRSF1B), Present study showed a highly significant difference between overall patients and controls. TNFSFR1B (rs1061622) SNP, CC and CT genotypes were dominant in controls and psoriatic patients, whereas the mutant TT genotype was dominant only in psoriatic patients. High risk of psoriasis in subjects had TT genotype than subjects carrying CC genotype. The response to treatment in the present study shows non-significant difference in the distribution of different genotypes of TNFSFR1B (rs1061622) polymorphism between responders and non-responders patients. Conclusion: These results may provide an additional evidence for association of TNF-α -308G/A and TNFRSF1B rs1061622, genes polymorphism to psoriasis susceptibility and disease severity and may serve as predictive and prognostic biomarkers.