Objective To translate the Consumer Health Activation Index (CHAI) from English to Chinese-language, and to test its reliability and validity. Methods According to the Brislin translation model, translation, back-translation, cross-cultural adaptation and pilot testing were performed to produce the Chinese version of the CHAI (CHAI-C). Then, 182 patients with chronic diseases were conveniently selected from 6 community health care institutions in Jiangsu province to test its reliability and validity. Results The overall Cronbach′s α coefficient of the CHAI-C was 0.812, and the test-retest reliability was 0.979. The content validity index of the scale (S-CVI/Ave) was 0.960, and the CVI of each item ranged from 0.800 to 1.000. Exploratory factor analysis identified three main factors, named as knowledge, self-efficacy and action, accounting for 68.784% of the total variance. Conclusion The CHAI-C has good reliability and validity in patients with chronic diseases, which can be used as a measurement tool to assess activation in chronic disease patients.