A total of 100 consecutive patients with primary symptomatic KOA were invited to participate in this study. Patients were recruited from the Outpatient Rheumatology Clinic at Mansoura University Hospitals. The study included also 100 consecutive non-KOA subjects matched for age, sex and BMI with KOA patients. All patients met the 2010 EULAR criteria for diagnosis of KOA and patients had to show evidence of radiological changes of KOA by plain radiography and Knee Ultrasonography. Blood samples were collected from all participants to test for ESR, CRP, fasting blood sugar and lipid profile. Assessment of carotid atherosclerosis is made by measurements of Carotid intima media thickness (cIMT). Comparison between KOA group and non-KOA group was done and revealed that cIMT differed significantly among the KOA subgroups based on KL grading being thickest in the KOA-KL4 subgroup of patients.The rate of presence of carotid plaques differed among the groups, with rate being highest in KOA-KL4 subgroup (79.2%), followed by KOA-KL3 subgroup (35.7%) and is lowest in KOA-KL2 subgroup (8.3%). These differences were significant (p < 0.001).