Obesity is still an actual subject because of its rapidly increasing prevalence. Although it is not a serious disease by itself, obesity plays an important role in the development of diabetes mellitus and cardiovasculer diseases. In this study, we aimed to investigate the relationship between insulin resistance and interleukin-6, leptin, hs-CRP and fibrinogen in obese and non-obese individuals.Methods: This study, which is an analytical study in the case-control type, was conducted on 329 adult individuals. Heights, weights, body mass indexes (BMI), waist circumferences, blood pressures, fasting blood glucose (FBG), total cholesterol, triglyceride, LDL-c, HDL-c, hs-CRP, leptin, IL-6, fibrinogen, and insulin levels were measured.Results: Of all the participants, 204 (62.0%) were female, 125 (38.0%) were male; 71 of them were of (21.5%) normal weight, 89 (27.1%) were overweight and 169 were (51.4%) obese. There was a significant correlation between low educational level and obesity (p<0.001). The married participants exhibited higher rates of being overweight and obese than other groups (p<0.001). There was a significant relationship between FBG, TG, HDL-c levels in male/female gender and BMI, statistically (p<0.05). In our study, a significant correlation was found between insulin, insulin resistance, hs-CRP, fibrinogen, leptin levels, low HDL-c levels and obesity (p<0.05). No statistically significant relationship was found between IL-6 and obesity (p>0.05). As a result of the multiple regression analysis, HOMA-IR, leptin ve hs-CRP levels was found as the effective basic factors on obesity. On the other hand, there was a significant relationship between high blood pressure and obesity (p<0.001).Conclusion: In our study, high fasting blood glucose, TG, insulin, insulin resistance, hs-CRP, fibrinogen, leptin and low HDL-c levels were found to be correlated with obesity. This correlation leads to many diseases, notably diabetes mellitus and cardio-vascular diseases.