Aim: There are two different types of diabetes mellitus, type 1 and type 2, with still unclear molecular mechanisms. In the present study, we aimed to investigate the role of small ubiquitin-like modifier 4 (SUMO4) M55V and nuclear factor kappa B1 (NFKB1)-94del/ins in type-2 diabetes mellitus. Materials and Methods: We analyzed SUMO4 M55V and NFKB1-94del/ins variants in 104 patients with type-2 diabetes and 124 healthy controls using the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) techniques. Results: The number of SUMO4 M55V MM genotype and M allele carriers was significantly higher in patients compared to the control group; however, no efficiency results were found related to NFKB1-94del/ins polymorphism. Conclusion: It was found that SUMO4 M55V polymorphism and type-2 diabetes were significantly associated with a possible SUMO4 region to type-2 diabetes susceptibility. This preliminary study showed that the distribution of SUMO4 M55V and type-2 diabetes mellitus in Turkish patients may form the basis of future research.