Purpose. The use of quetiapine as a drug to treat various substance use disorders as well as a drug of abuse is examined. Summary. Quetiapine's effectiveness in treating schizophrenia and bipolar disorder is well-known; however, growing evidence has indicated that it may be useful in the treatment of various substance use disorders. Small-scale studies have been conducted to investigate the potential benefit of quetiapine in patients dependent on alcohol, cocaine, and amphetamines. The results of these two studies provide some evidence that quetiapine may benefit patients diagnosed with a mental illness who are also dependent on cocaine, amphetamines, or both, though more rigorous studies are needed. An unforeseen use of antipsychotics, specifically quetiapine, as drugs of abuse has emerged. Since antipsychotics are not classified as controlled substances, the majority of clinicians may not consider the diversion of antipsychotics for recreational purposes, but evidence of this is increasing, particularly in incarcerated individuals. Intravenous quetiapine abuse was first reported in the literature in 2005. Although most cases of quetiapine abuse have been reported in the correctional setting, inappropriate quetiapine use within the community has been documented. Thus far, all of the documented cases have involved patients with a prior history of substance abuse. Clinicians must be cognizant of the potential for quetiapine as a treatment for substance use disorders and as a drug of abuse. Conclusion. Quetiapine is a promising treatment for substance use disorders alone or combined with other psychiatric diagnoses, such as bipolar disorder and schizophrenia. Quetiapine abuse has also been documented, particularly in the correctional setting.