Sixty cancer patients undergoing their first course of radiotherapy were assigned to one of two patient education conditions as they entered treatment: patients in the high-information condition were shown an audiovisual program, presenting procedural and sensory information about radiotherapy; patients in the low-information condition received standard care without exposure to the patient education program. On the basis of psychologic testing, patients were also classified on "vigilant-avoidant" and "repression-sensitization" coping style dimensions. Outcome variables, assessed during the first and last weeks of treatment (T1 and T2, respectively) induced ratings of treatment-related knowledge, state anxiety, and total mood disturbance. Preparatory patient education produced positive results regardless of coping style. Patients in the high-information condition showed significantly greater treatment-related knowledge (at T1) and less emotional distress (at T2). There was no significant main effect for coping style, nor was there an interaction effect (coping style by intervention condition). Results are discussed in terms of the manifest need for preparatory information in radiation therapy settings, the role of coping style factors, and the clinical utility of patient education interventions.