The purpose of this study was to examine the relation of depression and anxiety to cancer patients' medical decision-making. Participants were 79 rural and urban cancer patients undergoing chemotherapy. The four decisional styles of the Decisional Processing Model were the independent variables. Dependent variables were anxiety and depression, measured by Spielberger's State-Trait Anxiety and the Center for Disease Control Depression Scale, respectively. Consistent with the Decisional Processing Model, analysis suggested that patients make medical decisions by information seeking, information processing, advice following, or ruminating. Decisional style did not vary according to type or stage of cancer, prognosis, time elapsed since initial diagnosis, or whether cancer was initial or recurrent. Decisional style did not systematically vary with depression and anxiety suggesting how a person makes decisions is a stable personality trait. Thus, decision-making may follow a cognitive schema. It is likely that patients' decisional styles help to manage anxiety and depression when confronted with life-threatening illness. Implications for informed consent and patients' involvement in decision-making are discussed.