The use of left ventricular assist devices (LVADs) for advanced heart failure is becoming increasingly common. However, optimal timing and patient selection remain controversial. The aim of this study was to investigate outcomes of LVAD implantation for advanced heart failure in critically ill patients (INTERMACS 1 and 2). Between August 2010 and January 2020, 207 consecutive patients underwent LVAD implantation. Overall survival, major adverse events, and laboratory parameters were compared between patients in INTERMACS 1‐2 (n = 107) and INTERMACS 3‐5 (n = 100). Preoperative white blood cells, C‐reactive protein, procalcitonin, bilirubin, alanine transaminase, and lactate dehydrogenase were all significantly higher in INTERMACS 1‐2 when compared to INTERMACS 3‐5 (P < .05). During hospitalization following LVAD implantation, patients in INTERMACS 1‐2 were more likely to develop major infections (41.1% vs. 23.0%, P = .005), respiratory failure (57.9% vs. 25.0%, P < .001), mild (20.6% vs. 8.0%, P = .010), and moderate (31.8% vs. 7.0%, P < .001) right heart failure, and acute renal dysfunction (56.1% vs. 6.0%, P < .001). During a median follow‐up of 2.00 years (interquartile range (IQR) 0.24‐3.39 years), they had a higher incidence of thoracic (15.9% vs. 4.0%, P = .005) and gastrointestinal bleeding (21.5% vs. 11.0%, P = .042), as well as right heart failure (18.7% vs. 1%, P < .001). Risk of death was significantly higher in the INTERMACS 1‐2 group (hazards ratio (HR) 1.64, 95% CI 1.12‐2.40, P = .011). LVAD implantation in critically ill patients is associated with increased morbidity and mortality. Our results suggest that decision for LVAD should be not be delayed until INTERMACS 1 and 2 levels whenever possible.