Inadequate relief from cancer pain is an international health problem. The aim of this study was to document the prevalence and patterns of cancer pain management in the Republic of South Africa. The first phase of this study consisted of screening 263 patients to document the prevalence of cancer pain in varying settings. A total of 94 patients were experiencing cancer-related pain; this comprised 35.7% of the sample. Inpatients had a higher prevalence than outpatients, which is likely due to the fact that these patients are more acutely ill. Blacks (56.1%) had a higher prevalence of pain than whites (29.4%, P<0.005); this difference was most pronounced in the outpatient setting. Phase 2 consisted of asking 426 patients with cancer pain from different settings to complete a questionnaire that included the brief pain inventory and was designed to learn about their pain and how it was managed. Nearly one-third of the entire sample experienced 'worst pain' of severe intensity. There was little difference between the public and private cancer care centers. The lowest percentage of patients with severe 'worst pain' was in the hospice setting, but even in this group about one-fourth of the patients had peak pain that was severe. Of non-whites combined, 81% experienced 'worst pain' of moderate to severe intensity as compared to 65% of whites (P<0.001). Only 21% of patients reported that they had achieved 100% pain relief. Patients experienced interference in general activity, mood, walking, working, relations with others, sleeping, and enjoyment of life related to their pain. 30.5% of the entire sample had a negative score on the pain management index, a comparison of the most potent analgesic used by a patient relative to their worst pain. Of this group, 58.1% were experiencing severe 'worst pain'. Unrelieved cancer pain is a significant problem. Government and non-government leaders, educators, and practitioners must collaborate to address the barriers to effective pain management and to implement improvements in education, health policy, and health care delivery.