In this association study, we tested the hypothesis whether the estrogen receptor gene dinucleotide (TA) polymorphism is a risk factor for premature myocardial infarction in Caucasian women. We also investigated the relationships between estrogen receptor gene dinucleotide (TA) polymorphism and serum lipid levels. One-hundred and forty-one women with premature myocardial infarction were compared with healthy women. Cases and controls did not demonstrate a statistically significant difference in distribution of the estrogen receptor dinucleotide (TA) gene polymorphism alleles. Neither could we demonstrate the length of the dinucleotide (TA) repeats of the estrogen gene to be associated with premature myocardial infarction in Caucasian women. Subjects with larger alleles (both alleles of ≧19 repeats) did not differ in serum lipid levels (total, LDL, HDL cholesterol and triglycerides) from subjects with other genotypes. We may conclude that in Caucasian women the length of the dinucleotide (TA) repeat in the regulatory region of the α-estrogen receptor gene is neither associated with premature myocardial infarction nor with serum lipid levels.