This case study illustrates the use of cannabidiol (CBD) oil to decrease the addictive use of marijuana and provide anxiolytic and sleep benefits. Addiction to marijuana is a chronic, relapsing disorder, which is becoming a prevalent condition in the United States. The most abundant compound in the marijuana, which is called tetrahydrocannabinol (THC), has been widely studied and known for its psychoactive properties. The second most abundant component-CBD-has been suggested to have the medicinal effects of decreasing anxiety, improving sleep, and other neuro-protective effects. The mechanism of action for CBD has been suggested to be antagonistic to the psychoactive properties of THC in many locations within the central nervous system. Such action raises the issue of whether it might be beneficial to use CBD in isolation to facilitate withdrawal of marijuana use. The specific use of CBD for marijuana reduction has not been widely studied. The patient was a 27-y-old male who presented with a long-standing diagnosis of bipolar disorder and a daily addiction to marijuana use. In the described intervention, the only change made to the patient's treatment was the addition of CBD oil with the dosage gradually decreasing from 24 to 18 mg. With use of the CBD oil, the patient reported being less anxious, as well as settling into a regular pattern of sleep. He also indicated that he had not used any marijuana since starting the CBD oil. With the decrease in the dosage to 18 mg, the patient was able to maintain his nonuse of marijuana.