In gastrointestinal malignancies increased expression of matrilysin - MMP-7 - is often observed. Its high level positively correlates with clinical stage of malignancy and is a negative prognostic factor. This suggests a possible relationship between functional polymorphisms of the MMP-7 gene and susceptibility to development of colorectal cancer and an aggressive course of the disease.The aim of the study was to assess the effects of A/G functional polymorphism at -181 site of the MMP-7 gene promoter region on development and progression of colorectal cancer.Material and methods. In total, 184 patients treated surgically for colorectal cancer at the Department of General and Colorectal Surgery of the Medical University in Łódź in the years 2006-2009 and a control group of 205 cancer-free individuals with a negative family history for malignancy have been investigated. Polymorphic variants of the MMP-7 gene promoter region have been analysed using the RFLP-PCR method.Results. A statistically significant difference in distribution of genotypes has been found between the investigated group and the control group, and the OR analysis confirmed a relationship between the A/G [1.67 (1.03-2.72); p= 0.038] and G/G [2.12 (1.34-3.38); p = 0.018] genotypes and an increased risk of colorectal cancer. The risk of lymph node involvement was more than twice higher for the G/G genotype (OR = 2.83 (1.18-6.79); P = 0.017). In addition, the analysis of genotype distribution in patients divided into groups according to the T parameter of the TNM classification revealed a relationship between the G/G genotype and advanced tumour infiltration. No relationship between the investigated A/G polymorphism and the presence of distant metastases has been found.Conclusions. Obtained results indicate a possible relationship between -181 A/G polymorphism of the MMP-7 gene and malignant transformation of colorectal epithelial cells and progression of colorectal cancer. This suggests applicability of this polymorphism as a predisposing factor for the disease and a prognostic factor, which in the future may be useful in the management algorithm for colorectal cancer.