Introduction-Osteoporosis is a major health problem for postmenopausal women. Adjuvant hormonal therapy with aromatase inhibitors (AIs) in postmenopausal breast cancer patients further worsens bone loss. Bisphosphonates are able to prevent AI-induced bone loss, but limited data exists on their effect on bone structure. Our objectives were to: 1) examine the impact of AIs and non-AIs on hip structural geometry (HSA) of chemotherapy-induced postmenopausal women, and 2) determine if oral bisphosphonates could affect these changes.