The recent upsurge in global obesity and the recognition of the role of metabolic syndrome and other correlates of obesity in the etiology of breast cancer and other chronic diseases has created the impetus for renewed interest in the role of anthropometric measures in breast cancer risk. This case-control study was designed to evaluate the role of anthropometric variables in breast cancer susceptibility in an indigenous sub-Saharan African population drawn from midwestern and southeastern Nigeria, a population grossly underreported in the global epidemiologic literature. Study participants were 250 women with breast cancer who were receiving treatment in the surgical outpatient clinics and surgical wards of four university teaching hospitals located in midwestern and southeastern Nigeria, while the controls were 250 age-matched women without breast cancer or other malignant diseases being treated for other surgical diseases in the same institutions between September 2002 and April 2004. Waist:hip ratio (WHR) was associated with a significant 2.5-fold increased risk of premenopausal breast cancer (odds ratio [OR] = 2.56, 95% confidence interval [CI] 1.48-4.41] and a 2-fold increased risk of postmenopausal breast cancer (OR = 2.00, 95% CI 1.04-2.53). Increasing height conferred a modestly nonsignificant increased risk of premenopausal breast cancer (OR = 1.59, 95% CI 0.98-2.58). The study showed that WHR is a significant predictor of breast cancer risk in Nigerian women and measures to sustain increased physical activity and ensure healthy dietary practices are recommended to reduce the burden of obesity in the population.