The aim of this study was to evaluate bone mineral content (BMC), serum and urinary bone turnover parameters in patients with familial Mediterranean fever (FMF), an autosomal recessive disease characterized by recurrent episodes of inflammation of serous membranes. Demographic characteristics and MEFV mutations were defined in 48 children diagnosed with FMF (23 F, 25 M; median age 7.0 years (3.0-10.0)). We evaluated the blood counts, acute-phase proteins and serum and urinary bone turnover parameters during attack-free periods. The BMC and BA (bone area) of vertebrae L1-L4 were measured by DEXA. Thirty-eight age-, sex- and ethnicity-matched healthy children constituted the control group. Mean L1-L4 BMC in Group I (patients with two mutations) and II (patients with no or single mutations) were 15.49+/-5.99 g and 15.68+/-4.89 g, respectively, both significantly lower than the mean L1-L4 BMC of control patients, which was 19.59+/-6.7 g (p<0.05). Mean L1-L4 BMD in Group I, Group II and the control group were 0.466+/-0.066 g/cm(2), 0.487+/-0.085 g/cm(2 )and 0.513+/-0.079 g/cm(2), respectively. Mean z-scores in Group I, Group II and the control group were -1.87+/-0.74, -1.55+/-0.92 and -1.39+/-0.84, respectively. Mean L1-L4 BMD and z-score of Group I were lower than in the control group (p<0.05). ESR and SAA (serum amyloid A) levels were higher in Group I patients: 28.3+/-14.5 mm/h and 350+/-62 mg/l in Group I; and 20.5+/-11.7 mm/h and 190+/-68 mg/l in Group II, respectively. In conclusion, FMF patients had lower BMC, BMD and z-scores than a control group. We suggest that decreased BMD, BMC and z-score in FMF patients may be secondary to subclinical inflammation.