The present study was planned for bacteriological examination of S.aureus  associated with arthritis in chickens and characterization the molecular bases of virulence and antimicrobial resistance of isolated strains .In this study a total of 100 chickens (15 – 70 days) with arthritis symptoms, were collected from different chicken farms, swabs were taken from affected hock joints and cultivated on(Brain Heart Infusion broth, Baired Parker media and Manitol Salt agar media) for isolation of Staphylococcus aureus (S.aureus).The results revealed that  19 (19%) samples were positive for S.aureus isolation. Multiple antibiotic-resistant were observed in all S.aureus isolates, with the majority of isolates displaying resistance to erythromycin, amoxicillin and cefoxitin with a percent 52.6%,78.9% and 57.8% respectively. Detection of (mphC ,blaZ and mecA) resistant genes demonestrated that (20%) were positive for mphC gene ,(100%) positive for blaZ gene and (40%) positive for mecA gene. Amplification of (clfA, spa, coa and icaA) virulance genes of  Staphylococcus aureus by using PCR showed (100%) detection of clfA, spa and coa genes in all tested strains, while (40%) only of tested strains were positive for  icaA virulence gene. It could be concluded that S.aureus is one of the most important pathogenic organisms associated with chicken arthritis in Egypt, Studying of virulence and resistance genes is very important to know the danger and severity of the present microorganisms.