Extracorporeal life support with venoarterial extracorporeal membrane oxygenation (VA-ECMO) is used to assist circulation in patients with severe cardiogenic shock or cardiac arrest. The vasoactive-inotropic score (VIS) is a standardized calculation of vasoactive medication support which uses coefficients for each medication that converts them to an equivalent value. The purpose of this study was to assess the VIS as an early prognostication tool for survival to decannulation patients on adult VA-ECMO support. This was a single-center, observational cohort study of adult patients who received VA-ECMO support compared based on their survival to decannulation. The primary endpoint was the VIS at hour 24 postcannulation. Among the 265 patients included in this study, 140 patients (52.8%) survived to decannulation of VA-ECMO. At 24 hours postcannulation, a lower VIS was observed in the group that survived decannulation (6.5 ± 7.5 vs. 12.3 ± 16.9; p < 0.001). Multivariate analysis performed also demonstrates an association between 24-hour VIS and survival to decannulation (odds ratio 0.95; 95% confidence interval, 0.91–0.95). This study suggests that the 24-hour VIS may be an early prognostic indicator in patients on VA-ECMO patients.