The Vasopressin and Septic Shock Trial (VASST) compares the use of vasopressin to norepinephrine in patients with septic shock. This chapter includes an overview of the study design and interventions. It also outlines the primary and secondary outcomes used in this trial, as well as the results found. It also discusses some criticisms and limitations of the study. To help readers fully understand the impact of the VASST, this chapter includes a quick review of several post hoc analyses from the trial as well as other relevant studies, including some important post hoc analyses, in addition to other related studies. Finally, this chapter concludes with a case example and a suggested approach on how to clinically apply the results of the VASST.