OBJECTIVE: To evaluate the incremental effect of a graphic weigh-scale values clarification exercise to explicitly consider the personal importance of the benefits versus the risks in a woman's decision aid regarding postmenopausal hormone therapy. DESIGN: Randomized controlled trial. Intervention Decision aid including information on options, benefits and risks, and their probabilities either followed by: (1) a graphic weigh-scale values clarification exercise to explicitly consider the personal importance of each benefit and risk; or (2) a summary of the main benefits and risks to implicitly consider benefits versus the risks. SAMPLE: Two-hundred and one women aged 50-69 years from Ottawa, Canada, who had never used hormone therapy. OUTCOME: Perceived clarity of values, a sub-scale of the decisional conflict scale; congruence between personal values of benefits and risks (measured on 0-10 importance rating scale) and choices (accept, decline, unsure regarding preventive hormone therapy [HRT]) using discriminant function analysis. RESULTS: There were no statistically significant differences between interventions in perceived clarity of values and overall congruence between values and choices. Amongst those choosing HRT, there was a trend in those exposed to the graphic weigh-scale exercise to have better congruence between values and choices compared to implicit values clarification (P = 0.06). CONCLUSION: The use of the graphic weigh-scale exercise in a decision aid conveys no overall short-term benefit. Further study is needed to specifically determine effects in those changing the status quo and on the quality of patient-practitioner communication and persistence with decisions.