Objective: There are many studies demonstrating deteriorated ventricle and endothelium functions in familial Mediterranean fever (FMF) patients. As FMF is an autoinflammatory disease with an ongoing inflammatory activity and inflammation plays an important role in the development and progression of atherosclerosis in some of the rheumatic diseases, we aimed to investigate the early markers of atherosclerosis in patients with FMF by the measurements of serum paraoxonase-1 (PON-1) activity, mean platelet volume (MPV) and malondialdehyde (MDA) level. Methods: This study is a cross-sectional, observational study. Forty consecutive patients with FMF and twenty healthy volunteers were selected to form the study population. The diagnosis of FMF was based on Tel-Hashomer criteria. Serum PON-1 activity, MPV and MDA level were determined to examine their association with FMF. Student’s t-test, Mann-Whitney U test, Pearson correlation analysis were used for statistical analysis. Results: The mean PON-1 activity in FMF patients was significantly lower than in the healthy population (141.46±38.29 vs. 179.62±10.73 U/l, p<0.01). Serum MDA levels were the same between the groups (1.08±0.66 vs. 1.08±0.33 nmol/mL, p=0.99). MPV was higher in FMF patients than in the control l group (8.87±0.99 vs. 8.22±0.45 fl, p=0.04). PON, MPV and MDA levels were the same in FMF patients with acute attack and attack -free period. Conclusion: : Our results show that PON-1 activity is lower in patients with FMF. Reduced PON-1 activity and increased MPV, independent of the oxidative stress status of these patients, may lead to increased atherosclerotic propensity in FMF.