Background: Alopecia areata is an autoimmune disorder with a varied, typically relapsing or remitting nature. Numerous concomitant conditions, such as celiac, hypothyroidism, hyperlipidemia, type 1diabetes, and atherosclerosis, are linked to alopecia areata. Materials and methods: This study was performed on (86) subjects who were categorized into two groups; Group (1): included 43 healthy individuals. Group (2): included 43 patients diagnosed with alopecia areata. This group was divided into 2 groups: group A: 20 patients were treated by conventional therapy. Group B: 23 patients were treated by Platelet Rich Plasma (PRP) (local intradermal injection). Whole blood samples were used for genotyping of TCF7L2 polymorphisms (rs7903146). Results: Regarding TCF7L2 genotyping: CT, TT and CT+TT genotypes of TCF7L2 were significantly higher in cases compared to controls. There was no significant difference between different TCF7L2 genotypes among alopecia patients regarding to demographic data and Clinical findings except white hair before treatment. There was no significant variation between different TCF7L2 genotypes in PRP and steroid treated alopecia patients regarding to demographic data and clinical findings except exclamation mark in PRP treated group. Conclusion: TCF7L2 gens polymorphism is associated with alopecia areata, however there was no significant difference between PRP treatment and conventional therapy regarding to the different genotypes. Keywords: TCF7L2, Alopecia areata, PRP, Polymorphism