OBJECTIVE: Predicting in-hospital mortality rates following tricuspid valve surgery is imperative, especially in light of the recent advancements in treatment modalities. The Naples prognostic score serves as an indicator of systemic inflammation, malnutrition, and prognostic outcomes across a spectrum of medical conditions. In this investigation, we sought to assess the efficacy of the Naples prognostic score in predicting in-hospital mortality among patients undergoing tricuspid valve surgery. METHODS: A total of 360 consecutive patients diagnosed with severe tricuspid valve disease, who underwent tricuspid valve surgery, were included in this retrospective study. The study population was categorized based on the Naples prognostic score classification into two groups: low (0-1-2) and high (3-4). RESULTS: The study's primary outcome-in-hospital mortality-was significantly higher in patients with a high Naples prognostic score group than in those with a low Naples prognostic score group (35 [28.2%] vs. 8 [5.1%], p<0.001). In the receiver operating characteristic analysis, the Naples prognostic score optimal cut-off value of >2 predicted in-hospital mortality with 81.4% sensitivity and 62.5% specificity (area under the curve: 0.782 [95%CI 0.729-0.829, p<0.0001]). CONCLUSION: The findings of this study indicate that the Naples prognostic score serves as an independent predictor of in-hospital mortality among patients undergoing tricuspid valve surgery.