Objectives Diabetes is a chronic group of metabolic disorders those generally present with hyperglycemia hence insulin synthesis defects due to multifactorial causes in beta cells in the Langerhans islets of the pancreas. In the development of diabetes, genetic predisposition is as important as environmental factors. As a result of polymorphism studies in diabetic patients, many genes were associated with the development of diabetes. In our study, we aimed to represent the relationship between diabetes and certain variants of the Ghrelin (GHRL), Fat mass and obesity-associated protein (FTO) and Peroxisome proliferator-activated receptor-gamma coactivator (PGC-1 alpha) genes which are generally associated with diabetes and obesity. Methods One-hundred type 2 diabetes mellitus (T2DM) patients and ninety-four healthy volunteers were enrolled in our study. GHRL (rs4684677), FTO (rs8044769) and PGC-1 alpha (rs8192678) gene polymorphism studies were performed by the Real-Time PCR method. Results The carriers of the TT genotype for the FTO (rs8044769) and the GG genotype for the PGC-1 alpha (rs8192678) variants were found more frequently in the patient group, while the GHRL (rs4684677) did not differ between the groups. For the PGC-1 alpha (rs8192678) variant in the patient group, glucose and BMI levels were observed significantly higher in carriers of the GA genotype than those with the GG genotype. There was no statistical difference in the distribution of GHRL (rs4684677) alleles among the groups. Conclusions We conclude that the FTO (rs8044769) and PGC-1 alpha (rs8192678) variants are associated with T2DM in the Turkish population. However, there is no association between GHRL (rs4684677) and T2DM.