Given limited resources, it is crucial to establish a concise set of performance indicators for evaluating and tracking a hospital's performance. This study aimed to comprehensively investigate the existing evidence related to the identification, classification, and utilization of key performance indicators (KPIs) in the context of hospitals. This systematic scoping review was conducted following the Joanna Briggs Institute (JBI) methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews (PRISMA-SCR) extension. This review encompassed studies focusing on the evaluation of hospitals' performance, including those that introduced and implemented key indicators. The search, covering published and unpublished studies, spanned from October 25, 2022 (updated in December 2023), using databases, such as MEDLINE (via PubMed), Scopus, Web of Science, Emerald, ProQuest, and Google Scholar. Of 2,316 records screened by titles and abstracts, 70 complete reports were assessed. Among them, 46 studies were found to be irrelevant, and eight were included in the review studies and thus omitted. Finally, 16 studies were included in this research. The 10 most frequently examined KPIs in these studies followed this order: Average length of stay, rate of nosocomial infections, patient satisfaction rate, mortality rate, bed occupancy rate, incidents/errors, accidents/adverse events, waiting time, readmission rate, and mean cost per patient. The average length of stay and the rate of nosocomial infections emerged as the most frequently scrutinized indicators. The findings also showed that there is a higher level of emphasis placed on the dimensions of effectiveness and efficiency.