Background: The expression of MMP genes has been demonstrated to be associated with tumor invasion, metastasis and survival rate for a variety of cancers. The functional promoter polymorphism MMP-2 C-735T is associated with decreased expression of the MMP-2 gene. The aim of present study was to detect any association between MMP-2 C-735T and susceptibility to breast cancer. Materials and Methods: The MMP-2 C-735T polymorphism was studied in 233 women (98 with breast cancer and 135 healthy controls). All studied women were from Kermanshah and Ilam provinces of Western Iran. The MMP-2 C-735T polymorphism was detected using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: The frequencies of MMP-2 CC, CT and TT genotypes in healthy individuals were 59.3, 38.5 and 2.2%, respectively. However, in breast cancer patients, only CC (71.4%) and CT (28.6%) genotypes were observed (p=0.077). In patients the frequency of the MMP-2 C allele was significantly higher (85.7%) compared to that in controls (78.5 %, p=0.048). The presence of C allele of MMP-2 increased the risk of breast cancer by 1.64-fold [OR=1.64 (95%CI 1.01-2.7, p=0.049)]. The frequency of MMP-2 C allele was also higher in patients ${leq}40$ years (88.9%) than those aged ${geq}41$ years (67.5%, p=0.07). In addition, the frequency of MMP-2 C allele tended to be higher in patients with a family history of cancer in first-degree relatives (76.6%) compared to that without a family history of cancer (67.3%, p=0.31). Conclusions: Our findings indicate that the C allele of MMP-2 C-735T polymorphism is associated with increased risk of breast cancer. Also, the MMP-2 C allele might increase the risk of young onset breast cancer in our population.