Although clinicians are often expected to include patients in medical decision making, there is little data to assist clinicians in this process. The objective of this study was to investigate how patients make decisions and the role clinicians can play in this process in the context of how women decide about hormone replacement therapy.Twenty-three women who were deciding whether to take hormone replacement therapy, but who had not begun treatment, were interviewed individually using a semistructured protocol with open-ended questions. The interviews were audiotaped, transcribed, and converted into a database. The transcripts were labeled according to their content, and the database was used to identify common themes. The content of the women's statements were organized into nine descriptive categories. A common set of processes involved in patient decision making was identified and organized into a model of patient decision making. Four areas where clinicians might influence or assist patients in making decisions include the provision of information, the process by which patients selectively pay attention to some information, the patients' perception of their own health, and the patients' development of an explanatory narrative. This new model describes some of the complexity of the patient decision-making process and contributes to our understanding of the clinician's role. To examine its generalizability, the model should be tested on other types of patients making other medical decisions.