The purpose of the paper is to present the survey findings of two alternative methods (self-rating (SR) and third-person rating (TPR)) of measuring employee work engagement (EWE). The potential impacts of gender, job tenure, position, and work condition on TPR vs. SR were also investigated. A sample of 649 of hotel service workers, supervisors, and managers in China participated in the study. An accurate measure of employee work engagement serves as a leading indicator of turnover intention and an early diagnostic tool for sustainable human resource management. Despite its popularity as a work engagement measure, SR method has many limitations. This research attempted to demonstrate that TPR is a viable and better alternative measure of EWE. The results indicated that TPR does possess desirable measurement characteristics, such as convergent validity, nomological validity, and structure invariant. TPR also provides a more conservative, and perhaps more accurate as well, measure of EWE. The difference in mean EWE scores as measured by SR vs. TPR was found to be affected by the specific dimension under study, with the least observable absorption dimension the most affected. The difference was also found to be significantly higher for males than for females, bigger as an employee’s position moves higher, and larger as the length of job tenure increases. Additionally, the difference in satisfaction–EWE correlations, as measured by TPR vs. SR, were much higher when the work conditions were poor. For practitioners, the importance of this study lies in the fact that TPR, as a conservative measure of EWE, can play an important role in detecting early signs of employee troubles sooner and lead management to take timely actions, making human resource management more sustainable. For academics, the results that SR and TPR of EWE generally result in similar pattern of findings offer strong encouragement to build future research on EWE through the TPR method.