The objective of this study was to investigate the health beliefs of orthopaedic patients towards calcium supplements. Four dimensions will be explored: prevention and treatment, rehabi- litation, worthiness and safety, and behavior and perceptions. Data was collected between June and December, 2011. Subjects were patients, aged 15 years or older, admitted to the Orthopaedic Ward of Songklanagarind Hospital. The questionnaire composed of two parts: demographic characteristics and questions regarding beliefs of calcium supplements. The results showed a high level of belief for treatment of bone tumours (55.6%) while that for treatment of gout (41.6%) and osteoarthritis (32.9%) was at a moderate level. For rehabilitation and worthiness/safety, the beliefs in each item of the dimensions were at a moderate level, that was, 54.3% of them believed that calcium supplements consumption only, may completely replace the daily diet and 44.4% believed the more expensive the calcium supplements, the better the quality, while 37.9% believed it to be safer. With the behaviour and perceptions, 37.3% of the sample bought calcium supplements from direct sellers because they can provide accurate and reliable information. This study revealed that a high proportion of orthopaedic patients have inappropriate beliefs about calcium supplements. It’s a responsibility of health care teams to give them the right information that include the benefits, harmful effects, worthiness and safety of calcium supplements, and try to change their perceptions and create the proper attitudes about this.