Background Empathy is an important attribute in medicine, influencing both the process and outcome of consultations. However, there are no validated tools available in Japan to gather patient feedback on physicians' empathy. The Consultation and Relational Empathy (CARE) Measure developed in the UK is widely used internationally. Objectives To investigate the psychometric properties of a Japanese version of the CARE Measure. Method Following two cycles of translation and back translation, the Japanese CARE Measure was completed by 317 patients in a primary medical care clinic in Japan. Tests of internal reliability and validity included Cronbach's alpha, item-total correlations and factor analysis. Predicted associations between CARE Measure score and other variables were assessed by Spearman's rho. Results Low numbers of missing values (8.2-9.8%) and 'not applicable' responses (0-1.3%) suggested high acceptability and face validity of the Japanese CARE Measure. Internal reliability was high (Cronbach's alpha 0.984) and was reduced by the removal of any of 10 items. High corrected item-total correlations (0.897-0.946) suggested homogeneity. Factor analysis showed a single solution with high item loadings (0.917-0.957). Construct validity was supported by a significant relationship (Spearman's rho 0.74, P < 0.001) with overall satisfaction with the consultation. Conclusion The Japanese CARE Measure appears to be valid and reliable in a primary medical care setting. Further work is required to determine its ability to discriminate between doctors.