This single arm study will continue drug safety surveillance, and assessment of adherence, in patients with postmenopausal osteoporosis who have received monthly oral Bonviva in ML19930, the BonAdAsia study. All patients completing 6 months in ML19930 will continue to receive Bonviva (150mg po, monthly) for an additional 6 months. The anticipated time on study treatment is 3-12 months, and the target sample size is 500+ individuals.