Background Coronary artery bypass grafting (CABG) remains a cornerstone in the management of coronary artery disease, especially for patients with severe left ventricular dysfunction. The debate between on-pump and off-pump CABG techniques centers on their impact on postoperative outcomes, particularly the length of ICU stay, which has significant implications for patient recovery and healthcare resources. Objective This study aimed to compare the effects of on-pump and off-pump coronary artery bypass grafting on the length of ICU stay among patients with severe left ventricular dysfunction undergoing cardiac revascularization, with a view to optimizing postoperative outcomes and resource utilization in this high-risk patient population. Methods A longitudinal cross-sectional study was conducted, enrolling 78 participants scheduled for CABG at a single center over one year. Participants were divided into two groups: those undergoing on-pump CABG (n=44) and those undergoing off-pump CABG (n=34). Data collection focused on demographic information, clinical characteristics, and the length of ICU stay. Statistical analysis employed SPSS v25, utilizing means, standard deviations, and Independent t-tests to compare outcomes between the two groups. Results The study revealed that patients undergoing on-pump CABG had a significantly shorter mean ICU stay (4 ± 3.9 days) compared to the off-pump CABG group (5 ± 4.4 days), with a P value of 0.01. Further stratification showed that older patients and those with comorbidities such as diabetes and hypertension experienced longer ICU stays, irrespective of the surgical technique used. Conclusion On-pump CABG is associated with shorter ICU stays compared to off-pump CABG in patients with severe left ventricular dysfunction, suggesting that the on-pump technique may be preferable for optimizing postoperative recovery and resource allocation in this patient cohort.