Objective. To explore and compare the influences of individual-level cultural values and personal attitudinal values on the desire for medical information and self-involvement in decision making in Australia and China. Methods. A total of 288 and 291 middle-aged adults from Australia and China, respectively, completed an online survey examining cultural and personal values, and their desired level of self-influence on medical decision making. Structural equation modeling was used to test 15 hypotheses relating to the effects of cultural and personal antecedents on the individual desire for influence over medical decision making. Results. Similar factors in both Australia and China (total variance explained: Australia 29%; China 35%) predicted desire for medical information, with interdependence (unstandardized path coefficient βAustralia = 0.102, P = 0.014; βChina = 0.215, P = 0.001), independence (βAustralia = 0.244, P < 0.001; βChina = 0.123, P = 0.037), and health locus of control (βAustralia = -0.140, P = 0.018; βChina = -0.138, P = 0.007) being significant and positive predictors. A desire for involvement in decisions was only predicted by power distance, which had an opposite effect of being negative for Australia and positive for China (total variance explained: Australia 11%; China 5%; βAustralia = 0.294, P < 0.001; China: βChina = -0.190, P = 0.043). National culture moderated the effect of independence on desire for medical information, which was stronger in Australia than China (Z score = 1.687, P < 0.05). Conclusions. Study results demonstrate that in both countries, desire for medical information can be influenced by individual-level cultural and personal values, suggesting potential benefits of tailoring health communication to personal mindsets to foster informed decision making. The desired level of self-involvement in decision making was relatively independent of other cultural and personal values in both countries, suggesting caution against cultural stereotypes. Study findings also suggest that involvement preferences in decision making should be considered separately from information needs at the clinical encounter.