Informed and shared decision making are hallmarks of quality medical care. Although decision aids (e.g., brochures, decision boards, videos, interactive computer programs) can impart useful information, there is a dearth of work on theory-based approaches that help people clarify preferences and select a favored alternative. Decision counseling is a novel method that has been developed to address this need. In a decision counseling session, provider and patient identify personal values associated with decision alternatives, weigh the influence of relevant factors, clarify preference, and select an option from available alternatives. Decision counseling is described here in relation to 3 decision-making situations (i.e., having cancer screening, being tested for cancer risk, and joining a cancer chemoprevention trial). Preliminary findings suggest that decision counseling can help to clarify personal preferences related to health behavior choices and, thus, facilitate achievement of the ideals of informed and shared decision making.