With the growing attention given to psychological issues in oncology, it is increasingly likely that cancer patients will be asked to participate in empirical studies of psychosocial variables associated with the patient's diagnosis, treatment, and subsequent quality of life. Because of the lack of data concerning patient responses to these requests (which is necessary from patient care and methodological perspectives), the purpose of this study was to examine systematically the effect of two study characteristics (content and format) and several selected demographic variables on patients* willingness to participate in psychosocial research. The sample consisted of 62 cancer patients with varying diagnoses and treatments. Primary findings were that patients' willingness to participate in psychosocial research was, overall, quite high and did not appear to be related either to patient characteristics or to study characteristics. Data are discussed as a means of facilitating rigorous psychosocial oncology research and in the broader context of general physical medicine.