Sequence variants within the type V collagen (COL5A1) and tenascin C (TNC) genes have to date been shown to be associated with chronic Achilles tendinopathies and/or spontaneous Achilles tendon ruptures. Type V collagen and tenascin C are quantitatively minor components of tendon, while type I collagen is the major structural component. There is increased expression of the COL1A1 gene, which encodes for the alpha1 chain of type I collagen, in the painful Achilles tendon. A functional Sp1-binding site polymorphism (SNP rs1800012; IVS1+1023G>T) within this gene has been shown to be associated with several connective tissue disorders. The aim of this study was to determine whether the Sp1-binding site polymorphism within the COL1A1 gene is associated with chronic Achilles tendinopathies and/or spontaneous Achilles tendon ruptures. Achilles tendinopathy (n=85), Achilles rupture (n=41) and asymptomatic control (n=125) participants were genotyped for the COL1A1 Sp1-binding site polymorphism. There were no observed statistical differences in the genotype (p=0.602) or allele (p=0.694) distributions between the groups. In conclusion, this study has shown that there is no association between the Sp1-binding site polymorphism within the first intron of COL1A1 and Achilles tendinopathy or Achilles tendon rupture within the population studied.