Introduction: Resistin and C-reactive protein secreted from adipose tissue, have endocrine, paracrine and autocrin effects on most metabolism and inflammatory processes. Data available shows associations between inflammation, adipokines and cancer. Medullary thyroid cancer constitutes 5 to 10 percent of thyroid cancer. The goal of this study was to assess serum resistin levels and C-reactive protein in patients with medullary thyroid carcinomas. Materials and Methods: In this study, 90 participantswith medullary thyroid cancer (21 males 29±13.91 and 24 females 29.0±14.52 years), and controls (24 males 23.08±11.58 and 21 females 31.52±14.38 years old) were selected. Resistin and C-reactive protein levels were determined in both groups with ELISA methods.  Height and weight of individuals were measured and body mass index was calculated. Results obtained by t-test were analyzed using the Medcalc version 13.5. Results: Between the two groups in terms of age and BMI differences were not statistically significant. The geometric mean of logarithm transformed differed significantly resistin in the patient group and control groups (1.44 and 2.36 respectively) (P=0.009). Mean C-reactive protein between the control and patient groups was not significantly different (p>0.05). Conclusion: It seams that significant differences in serum levels of Resistin in MTC and control group can be used as an indicator to help confirm the diagnosis of medullary thyroid carcinomas.