OBJECTIVES: To translate and examine the validity and reliability of the Malay version of the Osteoporosis Self- Efficacy Scale (OSES-M) among type 2 diabetes mellitus (T2DM) outpatients and to determine the best cut-off value with optimum sensitivity and specificity.  METHODS: A standard “forward-backward” translation procedure was used to create the Malaysian version of the OSES-M from the original English version, which was then validated with a convenience sample of 250 T2DM outpatients. All data were collected from the Penang General Hospital, Penang, Malaysia. Instruments consisted of the Malaysian version of OSES and a socio-demographic questionnaire. The sensitivity and specificity of the OSES-M was calculated using receiver operating characteristic curve analysis. Validity was confirmed using face (Fleiss' kappa), content (Lawshe’s quantitative approach) and construct validity (factor analysis). Reliability was assessed using Cronbach’s alpha and corrected item-total correlations between the scales and their corresponding items. Spearman’s rank correlation used to assess test–retest reliability.  RESULTS: By employing the recommended scoring method, the mean score of OSES-M was 731.74± 197.15. Fleiss' kappa, content validity ratio range and content validity index were 0.99, 0.75-1 and 0.96, respectively. Two factors were extracted from exploratory factor analysis and were confirmed through confirmatory factor analysis. Internal consistency and test–retest reliability were 0.92 and 0.86, respectively. The optimum cut-off point of OSES-M to predict osteoporosis/osteopenia was 858 with 85% sensitivity (95% CI 0.76-0.9) and 74.5% (95% CI 0.65-0.82) specificity. The area under the curve for OSES-M in identifying osteoporotic subjects was 0.86 with 95% CI 0.8-0.92 (P<0.01).   CONCLUSIONS: The findings of this study indicate that the OSES-M is a valid and reliable instrument for measuring osteoporosis self-efficacy in the Malaysian clinical setting and research practice.