Background: Pegylated liposomal doxorubicin (PLD) was shown to have comparable efficacy to doxorubicin, with significantly reduced cardiotoxicity. This study evaluated the cardiotoxicity and efficacy of the PLD-based regimen compared with those of the doxorubicin-based regimen as adjuvant therapy for early-stage breast cancer (BC). Methods: In this open-label, randomized controlled trial, patients with early-stage BC were assigned to receive either 4 cycles of PLD (study group) or doxorubicin (control group) plus cyclophosphamide followed by 4 cycles of docetaxel/paclitaxel. The primary endpoint was cardiotoxicity. Results: Between November 2017 and September 2019, 247 patients (study group, n = 131; control group, n = 116) were enrolled. Incidence rates of abnormal left ventricular ejection fraction (LVEF, 0 vs. 1.7%) and congestive heart failure (0.0% vs. 0.9%) were similar between the two groups (all P > 0.05). A lower proportion of elevated high-sensitivity cardiac troponin T (3.8% vs. 30.2%, P < 0.001) was observed in the study group. The 5-year disease-free survival (82.7% vs. 83.8%) and overall survival (90.4% vs. 91.6%) rates were comparable (all P > 0.05). Grade 3-4 adverse events in the study group were significantly less than in the control group (43.5% vs. 61.2%, P = 0.005). Conclusion: The PLD-based regimen for early-stage BC showed significantly lower rates of elevated hs-cTnT and grade 3-4 AEs with comparable efficacy to the doxorubicin-based regimen.