Rational-emotive behavior therapy (REBT) is a widely utilized treatment approach for many mental disorders, but it has been “relatively neglected in the professional scientific literature” (Ellis 2003b). This neglect has been attributed in part to a lack of solid REBT outcome studies, which in turn stems from the difficulty of measuring constructs of interest in REBT, such as irrational beliefs, via self-report measures. In light of these concerns, the current paper aims to identify the potential utility of behavioral analogue laboratory tasks for advancing the understanding of mechanisms in REBT, as well as treatment outcome using this therapeutic approach. Specifically, we focus on the utilization of behavioral measures of distress tolerance and their application to the key REBT construct of frustration intolerance. In identifying the parallels across distress tolerance and frustration intolerance, we consider how the incorporation of distress tolerance tasks into REBT research can be useful in evaluating the role of frustration intolerance in the initiation, maintenance, and treatment of disordered behavior across a broad range of clinical disorders.