Background: An autoimmune disease that impacts both articular and extra-articular organs (e.g., eye, skin, and nervous system), progressive systemic rheumatoid arthritis (RA) is a pathological condition. We aimed to measure the serum level of neutrophil extracellular traps (NETs) in RA patients and to detect the correlation between NET level and RA activity. Also to study the relation between NET level and cardiovascular affection in RA patients by measuring the carotid intima media thickness. Patients and methods: This study was conducted on 50 RA patients diagnosed according to the American College of Rheumatology and European League Against Rheumatism 2010 diagnostic criteria for RA, and 50 apparently healthy volunteers matched with patients in sex and age for evaluation of the NET level. All patients underwent the following: full clinical assessment, laboratory investigations, radiographic assessment and wrist and measurement of carotid intima media thickness by ultrasound. Results: There was elevation in total cholesterol, triglycerides, LDL levels and reduction in HDL level in patients. There was increased level of MPO level in RA patients' group with significant difference between the RA and control group (P<0.05). There was significant positive correlation between MPO level and clinical, laboratory and radiological findings of the patients (P<0.05). Conclusion: The serum level of NETs is increased in RA patients and correlated with rheumatoid disease activity detected by MSUS and DAS -28. Also, the serum level of NETs could be considered a useful biomarker for the early prediction of subclinical atherosclerosis and cardiovascular affection in RA patients.