OBJECTIVE: To conduct a systematic review of the effect of ibandronate on bone mineral density (BMD) and fractures in postmenopausal women(PMW). METHODS: We followed the Cochrane collaboration methodology to identify randomized placebo-controlled trials comparing PMW receiving ibandronate to those not receiving ibandronate. Trials were included in our review if they had study duration of ONE year or longer and reported BMD or fracture incidence as outcomes. A priori hypotheses dealing with mode and frequency of administration, dosage, study duration and severity of osteoporosis were developed to help explain heterogeneity of treatment effects. Heterogeneity testing was conducted using regression models. All analyses were performed using Comprehensive Meta-Analysis, version 2.2, software. RESULTS: Nine trials met eligibility criteria. The trials included a total of 8784 women; 6111 received ibandronate and 2673 placebo. Study results were reported at one, two and three years for five, two and two studies, respectively. Ibandronate dose and frequency varied across studies and all trials had > one treatment arm. In all studies, ibandronate was found to increase BMD in the spine and hip compared to placebo; the average increase in spine BMD was about 4% and hip BMD about 2.75%. The BMD increase varied significantly by severity of osteoporosis, mode and frequency of administration, dosage, and study duration. Only two studies reported data on fractures. In one study (Chesnut et al, JBMR 2004), ibandronate reduced the risk of vertebral fractures but not non-vertebral fractures compared to placebo after three years of treatment. In the other study (Recker et al, Bone 2004), risk reduction was observed for neither vertebral nor non-vertebral fractures. CONCLUSIONS: Ibandronate appears to increase BMD and reduces the incidence of vertebral fractures but not non-vertebral fractures. Additional data are required to better assess the impact of ibandronate on BMD and fractures in postmenopausal osteoporosis.