The co-occurrence of substance use disorders with anxiety disorders and/or posttraumatic stress disorder has been widely documented and when compared to each disorder alone, consistently linked to increased risk for a host of negative outcomes including greater impairment, poorer treatment response, and higher rates of symptom relapse. This article focuses on recent advances in the understanding and effective treatment of this common and highly complex comorbidity. Prevalence and epidemiological data are introduced, followed by a review of contemporary models of etiology and associative pathways. Conceptualizations of effective treatment approaches are discussed alongside evidence from the past decade of clinical research trials. Highlighted are ongoing questions regarding the benefit of sequential, parallel, and integrated approaches and the necessity of further investigation into the mechanisms underlying treatment efficacy. Lastly, recent contributions from neuroscience research are offered as a promising bridge for the development and testing of novel, interdisciplinary treatment approaches.