In a population-based cohort of 1604 post-menopausal women free of known cardiovascular disease, the present study identified the following: firstly, LV end-diastolic volumes and LA maximal volumes were lower in women using MHT ≥ 3 years compared to those who had never used MHT after accounting for potential confounders. Secondly, MHT use significantly modified the relationship between advancing age and LV end-diastolic volume, LV end-systolic volume and LA maximal volume. Thirdly, timing of commencement of MHT in relation to the onset of menopause had no discernible impact of LV or LA volumes.