Background: Botanicals and herbal combinations are among the most common complementary and alternative medicine (CAM) approaches used by cancer patients both for cancer treatment and management of cancer symptoms. Despite their widespread use, however, the safety and efficacy of many botanicals has not been established in controlled clinical trials. Objectives: This article reviews the published evidence for the safety and clinical benefit of botanicals used in the treatment of cancer and cancer symptom management and describes the continuing clinical trials of botanicals with applications in oncology. Methods: Literature searches were conducted in PubMed, EMBASE, Cochrane Clinical Trials databases, Pharmaprojects and CRISP (Computer Retrieval of Information on Scientific Projects) clinical trials databases. Conclusion: A number of botanicals have shown promise for cancer symptom management but need further study. A limited number of multi-agent nutritional supplement approaches are being explored in clinical trials. Botanical immunomodulators and botanical products shown to affect pathways of angiogenesis, apoptosis and cell signaling in vitro have stimulated research interest and may broaden the range of available cancer treatments.