Research has demonstrated that patients with cancer experience cognitive deficits, often due to aggressive anticancer treatments. In this article, we critically review the interventional studies that have been conducted to investigate beneficial effects on cognitive function in cancer patients. Pharmacological agents that have been studied include psychostimulants, such as methylphenidate and modafinil, erythropoietin, and hormonal (supplement) treatments for patients who receive hormonal suppression therapy. In addition, several cognitive rehabilitation programs have been evaluated in cancer patients. Recently, the approach of physical exercise to treat cognitive deficits has received great interest, and findings from novel studies are keenly anticipated. Although, in general, the studies reviewed were well designed, future studies may wish to include larger sample sizes and pay more attention to the accurate assessment of cognitive function.