High-risk patients with rheumatic heart disease (RHD) who were undergoing valve replacement surgery (VRS) were not identified entirely. This study included 1782 consecutive patients with RHD who were undergoing VRS to explore the relationship between hypoalbuminemia and adverse outcomes and to confirm whether hypoalbuminemia plays a role in risk evaluation. A total of 27.3% of the RHD patients had hypoalbuminemia. In-hospital deaths were significantly higher in the hypoalbuminemic group than in the non-hypoalbuminemic group (6.6% vs 3.1%, P = 0.001). Hypoalbuminemia was an independent predictor of in-hospital death (OR = 1.89, P = 0.014), even after adjusting for the Euro score. The addition of hypoalbuminemia to Euro score enhanced net reclassification improvement (0.346 for in-hospital death, P = 0.004; 0.306 for 1-year death, p = 0.005). A Kaplan-Meier curve analysis revealed that the cumulative rate of 1-year mortality after the operation was higher in patients with a new Euro score ≥6. These findings indicated that hypoalbuminemia was an independent risk factor for in-hospital and 1-year mortality after VRS in patients with RHD, which might have additive prognostic value to Euro score.