The theory that cases with thyroid disfunction have several lipid metabolism disorders has been suggested in previous studies but there were no previous studies about visfatin levels of patients with thyroid disfunction. In the study, it is aimed to research the role of visfatin in hypothyroid and subclinical hypothyroid status related to dislipidemia after determining the visfatin levels before and after Levothyroxin treatment. Patients with hypothyroidism and subclinical hypothyroidism were enrolled in the study. Patients were chosen randomly and divided into three groups according to their body mass indexes. After first physicial examination, patiens were given Levothyroxin treatment and were to be followed regularly. Total, 43 patients were enrolled in our study; 18.6% of them were hypothyroid and 81.4% were subclinical hypothyroid. 37 patients were female (86%) and 6 were male (14%). Mean age was 45.02 +/- 13.23 (16-74) years. After they had become euthyroid and were given Levothroxin treatment, statistically, visfatin levels decreased significantly in all patients (p=0.008, p<0.001). In addition, after Levothyroxin treatment, visfatin levels decreased dramatically in all overweight and obese patients [p=0.010 (for normal weights), p<0.001 (overweights), p=0,010 (obeses)]. After Levothyroxin treatment, serum total cholesterol and LDL cholesterol levels decreased significantly too, but HDL cholesterol levels did not change [p=0.001 (TC), p=0.003 (LDL), p=0.101 (HDL)]. Visfatin levels were positively correlated with TSH levels and negatively correlated with FT3 and FT4 levels. On the other hand, visfatin levels were positively correlated with serum total cholesterol and LDL cholesterol levels and negatively correlated with serum HDL cholesterol levels. Visfatin may have important effects on hypothyroidism and subclinical hypothyroidism related dislipidemia. Due to the likely effects of visfatin, following up visfatin levels may provide a guide for treatment in these conditions.