Tennis elbow defines a condition of pain and tenderness over the lateral epicondyle of the humerus. The exact aetiology of the injury is not yet fully understood. The major constituent of tendons is type 1 collagen which is encoded by COL1A1 gene. The aim of the study was to determine whether Sp1 binding site polymorphism (SNP rs1800012; 1546G/T) within the intronic region of COL1A1 gene is associated with tennis elbow. One hundred and three tennis elbow patients and one hundred and three healthy subjects without any history of previous ligament or tendon injuries were recruited for this genetic association study. All participants were genotyped for the COL1A1 Sp1 binding site polymorphism by using PCR-RFLP method. There were no observed statistical differences in the genotype (p = 0.17) or allele (p = 0.11) distributions between the groups. G allele frequency in patients and controls was 82.5% and 76.21%, and T allele frequency was 17.5% and 23.79% respectively. This study has shown that there is no association between this polymorphism and tennis elbow within the population studied. (C) 2014 Elsevier B.V. All rights reserved.