Abstract: The purpose of this study was to carry out a comparative study to investigate the effect of lipid profile, oestradiol and obesity on the risk of a woman developing breast cancer. This study was carried out at the Komfo Anokye Teaching Hospital (KATH), Peace and Love Hospital, Oduom, Kumasi and Redeemed Clinic, Nima, Accra between May 2002 and March 2003. In this study, 200 consented women comprising 100 breast cancer patients (43 pre- and 57 post-menopausal) and 100 controls (45 pre- and 55 post-menopausal) with similar age range (25 to 80 years) were assessed for lipid profile, oestradiol and BMI. There was a significant increase in Body Mass Index (BMI) (p = 0.011), Total Cholesterol (TC) (p<0.001), triglyceride (p = 0.026) and low density lipoprotein (LDL-cholesterol) (p = 0.001) of the breast cancer patients compared to the controls. With the exception of oestradiol (EST) that decreased, the lipid profile generally increased with age in both subjects and controls with the subjects having a much higher value than the corresponding control. There was also a significant positive correlation between BMI and TC (r2 = 0.022; p = 0.002) and also between BMI and LDL-cholesterol (r2 = 0.031; p = 0.0003). Apart from EST and LDL-cholesterol that were increased significantly only in the postmenopausal phase in comparison to the controls, BMI, TC and TG were increased in both pre-menopausal and post menopausal phases with HDL-cholesterol remaining unchanged. This study confirms the association between dyslipidaemia, BMI and increased breast cancer risk.