The impact of several environmental and genetic factors on diabetes and its complications is well documented. It has also been established that cytokines play a key role in the regulation of immune responses which have been shown to be important in the pathogenesis of diabetes. Studies showed that single-nucleotide polymorphisms within the -592 region of interleukin-10 (IL-10) are associated with the regulation of its expression. In this study, we aimed to find polymorphisms of this region that may be associated to type 2 diabetic (T2D) patients with and without nephropathy. In this study, peripheral blood samples were collected from 100 T2D patients without nephropathy, 100 T2D patients with nephropathy, and 100 healthy controls. DNA was extracted, and a polymerase chain reaction-restriction fragment length polymorphism technique was performed to examine the polymorphisms within the -592 region of the IL-10 gene. Our results showed a significant difference between the genotypes and alleles of the -592 region of IL-10 in nephropathic and non-nephropathic patients in comparison to the healthy controls. The differences between the two patient groups in relation to genotypes and alleles were not significant. Results of this study suggest that the functional gene polymorphism of IL-10 reported here may play an important role in the pathogenesis of diabetes, but it seems that these polymorphisms do not have an effect on the nephropathic complications of the disease.