The aim of this study was to investigate whether functional polymorphisms in the promoter of matrix metalloproteinase-1 (MMP-1), MMP-2 and MMP-9 genes were associated with susceptibility to knee osteoarthritis in the Turkish population. The MMP-1 -1,607 1G/2G (rs1799750), MMP-2 -1,306 C/T (rs243865), and MMP-9 -1,562 C/T (rs3918242) polymorphisms were determined by polymerase chain reaction-restriction fragment length polymorphism assay in 157 patients diagnosed with knee osteoarthritis based on the criteria of American College of Rheumatology and in 84 controls in Mersin, Turkey. Genotype distributions and allele frequencies of MMP-1, MMP-2, and MMP-9 gene polymorphisms were compared between the patients and controls. There were significant differences between the groups regarding the genotype distribution of MMP-1 polymorphism (P = 0.001). The frequencies of 1G/1G and 1G/2G genotypes were significantly higher in the knee osteoarthritis than in the controls (P = 0.002, and P = 0.006, respectively). In addition, 1G allele frequency of MMP-1 gene was higher in the patients than in the control group (P = 0.0001). The genotype distributions and allele frequencies of MMP-2 and MMP-9 gene polymorphisms did not differ between the osteoarthritis and the control groups (P > 0.05). These findings suggest that the -1,607 1G/2G polymorphism in the MMP-1 gene may contribute to susceptibility to knee osteoarthritis in the Turkish population.