PURPOSE: To determine the self-reported prevalence rates for cancer, non-cancer, and both cancer and non-cancer pain and to determine if there were differences in demographic, clinical, and pain characteristics among the three pain groups. METHODS: Patients were screened in outpatient oncology clinics for the presence of pain and/or analgesic use. Patients who reported pain completed the study questionnaires. RESULTS: A total of 1790 patients were available for screening in the outpatient clinics and 1549 (86.5%) completed the screening questionnaire. Out of them, 332 (21.4%) reported pain or used analgesics. Of the 217 patients who completed the study questionnaires, 53% had only cancer pain (pain due to cancer and/or treatment), 25.3% had non-cancer pain, and 21.7% had both cancer and non-cancer pain. No differences were found, among the three pain groups, in pain intensity or pain duration. However patients in the cancer and non-cancer pain group had higher pain interference scores, higher severity scores for various pain descriptors, and a higher number of pain locations. CONCLUSIONS: These findings suggest that outpatients with a combination of cancer and non-cancer pain may be at greater risk for under-treatment of pain. Oncology clinicians and primary care providers need to perform a comprehensive pain assessment of all oncology patients in order to be able to formulate an effective pain management plan.