© 2015 by the American Society for Artificial Internal Organs. Ventricular assist device patients (VAD) are at increased risk for thromboembolism. Biomarkers of hemolysis, such as lactate dehydrogenase (LDH) and poorly controlled international normalized ratio (INR) has been identified as predictors of thromboembolism. Patients aged 19 years and older who had a continuous flow VAD placed from 2006 to 2012 were included in this study (N = 115). We assessed the relationship of LDH elevation (≥600 IU/L) at different time points and thromboembolism. Over the 51.3 person-years of follow-up, a total of 23 first thromboembolic events occurred. Patients with elevated LDH on the day of VAD implantation had an increased risk for thromboembolism (hazard ratio [HR]: 4.72, 95% confidence interval [CI]: 1.44-15.4; p = 0.01). There was an increased risk of thromboembolism with early LDH elevation within the first month post-VAD (HR: 4.95, 95% CI: 1.69-14.4; p = 0.003) and estimated glomerular filtration rate <30 before VAD implantation (HR: 4.74, 95% CI: 1.12-20.1; p = 0.0346), whereas there was a decreased risk with good anticoagulation control (HR: 0.30, 95% CI: 0.10-0.86; p = 0.0247). Our study is the first to highlight the association between LDH elevation on the day of implantation and post-VAD thromboembolism. This study details the increased risk of thromboembolism with early LDH elevation and the importance of maintaining time in therapeutic INR range.