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Background: There are citrullin peptides in Rheumatoid Arthritis (RA) patients that are changed by Peptidyl Arginine Deiminase enzymes (encoded by PADI genes). An association between RA and PADI-4 haplotypes has been reported by researchers. The aim of this study is evaluation of PADI-4 Gene polymorphism in patient with Rheumatoid Arthritis referring. Methods and Materials: In this cross-sectional study we extracted the genomic DNAs from the whole blood samples of 50 patients with RA ( on the basis of ACR criteria) referring to Emam Reza hospital in Mashhad and a control group involving 50 healthy khorrasanian participants. DNA genom was extracted with nonenzymatic salting out method. Genotypes were determined by PCR simple sequence specific primers (PCR-SSP). Data were analyzed with Chi-Square and Fisherexact Test. Results: 58% of the patients had genotypes of 1and 2 38%: 1,4, 2%: 1b,2 ,and 2%: 2,4 .In the control group, 72% had genotype 1,2 22%: 1 and 4, 6%: 1b,2 while none of them had genotype 2,4. Conclusion: There was not any significant relationship between the presence of different PADI-4 genotypes and RA in Khorrasanian population