No previous study has examined knowledge, health beliefs and health-related behaviours in first-degree relatives (FDRs) of osteoporosis sufferers, especially focusing on Asian women. This study explored osteoporosis knowledge, beliefs and behaviours of women with a family history of osteoporosis, and drew a comparison with women with no such history. This study recruited women at a large public health centre in northern Taiwan. A questionnaire was applied on FDRs and non-FDRs women with a focus on osteoporosis knowledge, health beliefs and behaviours. Descriptive analysis was initially conducted. Differences between FDRs and non-FDRs were rated via Student's t-tests for continuous variables and the chi-squared test for categorical variables. Overall, most of the participants were aware of some osteoporosis-related information but the proportions of correct responses to the questions that tested knowledge between FDRs and non-FDRs were only 44.0% and 42%, respectively. Meanwhile, participants in the FDRs group not only reported higher concern in developing the disease, but also perceived higher barriers compared with the non-FDRs group. As the study demonstrates, for health-related behaviours, the FDRs group did not undertake actual preventive behaviours, and only bone mineral density screening behaviour differed significantly from the non-FDRs group. This study highlights the inadequate information on osteoporosis and constraining beliefs of FDRs women. Additionally, as preventative behaviours for osteoporosis were not noted in FDRs group, community health nurses and researchers should make efforts to assist and encourage women to take practical preventative behaviours. This investigation reviews the knowledge, beliefs and behaviours of the FDRs group for Taiwanese women with osteoporosis. The results of this work can be used to provide effective implementation guidelines for preventing osteoporosis especially for women with a family history of the disease.