Objective The decisional conflict scale (DCS) measures the perception of uncertainty in choosing options, factors contributing to decision conflict and effective decision making. This study examined the validity and reliability of the Chinese version of the DCS in Hong Kong Chinese women deciding breast cancer (BC) surgery. Method A Chinese version of the 16‐item DCS was administered to 471 women awaiting initial consultation for BC diagnosis. Confirmatory factor analysis (CFA) assessed the factor structure. Internal consistency, and convergent and discriminant validities of the factor structure were assessed. Results CFA revealed the original factor structure of the DCS showed poor fit to this sample. Exploratory factor analysis revealed an alternative three‐factor structure, Informed and Values Clarity, Uncertainty and Effective Decision and Support, was optimal. Cronbach's alpha ranged from 0.51 to 0.87. Correlations between decision‐making difficulties and satisfaction with medical consultation demonstrated acceptable convergent validity. Construct validity was supported by correlations between decision regret and psychological distress. Discriminant validity was supported by differentiation between delaying and non‐delaying decision‐makers. Conclusions The three‐factor DCS‐14 is a valid and practical measure for assessing decisional conflict in deciding BC surgery. It shows good potential for use in assessing decision satisfaction for women diagnosed with BC.