Transposition of the great arteries (TGA) requires early surgical repair during the neonatal period. Several preoperative factors have been identified for the postoperative poor outcome after arterial switch operation (ASO). However, the data remain uncertain an association. Therefore, we investigated the preoperative factors which affect the early postoperative outcomes. Between March 2005 and May 2012, a retrospective study was performed which included 126 infants with an ASO for TGA. Preoperative data included the vasoactive inotropic score (VIS) and baseline hemodynamics. Early postoperative outcomes included the duration of mechanical ventilation, the length of stay in the intensive care unit and hospital, and early mortality. Multivariate linear regression and receiver operating characteristics analysis were performed. The duration of mechanical ventilation was significantly correlated with the preoperative mechanical ventilator support and VIS, and CPB time. On multivariate linear regression analysis, a higher preoperative VIS, preoperative B-type natriuretic peptide (BNP) level, and the CPB time were identified as independent risk factors for delayed mechanical ventilation. Preoperative VIS (OR 1.154, 95 % CI 1.024–1.300) and the CPB time (OR 1.034, 95 % CI 1.009–1.060) were independent parameters predicting early mortality. A preoperative VIS of 12.5 had the best combined sensitivity (83.3 %) and specificity (85.3 %) and an AUC of 0.852 (95 % CI 0.642–1.061) predicted early mortality. Our results suggest that preoperative VIS and BNP can predict the need for prolonged postoperative mechanical ventilation. Moreover, preoperative VIS may be used as a simple and feasible indicator for predicting early mortality.