Many cancer patients suffer from pain, sleep, and mood problems and are using cannabis to relieve these symptoms. Cannabis may provide such relief but may also produce negative side effects including cognitive impairment, an especially problematic issue for cancer patients, indicating more research on cannabis use in the cancer context is required. In this endeavor, the present study seeks to compare the use of hemp-derived CBD (Cannabidiol) with and without THC (Delta-9-tetrahydrocannabinol) versus placebo on measures of sleep, pain, mood, subjective and objective cognitive functioning, and quality of life within 185 cancer patients.