ABSTRACT Familial Mediterranean Fever (FMF) is an inherited autoinflammatory disease. In this study, we aimed to assess chromosomal DNA damage and cell proliferation by using cytokinesis-block micronucleus cytome (CBMN-cyt) assay in the peripheral blood lymphocytes of untreated FMF patients carrying M694V and R202Q mutations, which are the most common MEFV gene mutations in Turkish society. The study included 20 untreated FMF patients with M694V and R202Q mutations and 20 healthy individuals of similar age and sex as the control group. Micronucleus (MN), nucleoplasmic bridges (NPBs), and nuclear buds (NBUDs) were scored in the obtained bi-nucleated (BN) cells. Additionally, the nuclear division index (NDI) was calculated using the scores of mononuclear, binuclear, and multinuclear cells. We found that MN and NPBs frequencies in FMF patients were significantly higher than in controls, and number of metaphases was significantly lower (respectively, p < 0.05, p < 0.01, and p < 0.01). However, there was no significant difference in NBUDs frequencies and NDI values between FMF patients and controls (p > 0.05). Our study is the first to evaluate FMF patients’ lymphocytes using the CBMN-cyt assay, as no previous research has been found in this respect. Increased MN and NPB frequencies may be useful as biomarkers for chromosomal DNA damage, and may indicate a potential for elevated cancer risk in untreated FMF patients.