Key Performance Indicators (KPIs) are a significant part of every successful construction project. Establishing KPIs that provide objective criteria for measuring project success is common in performance measurement on construction projects. A presumption is made that a project is successful if finished on time, within the agreed budget, and with the desired quality, often known as the "iron triangle." According to the evidence, this is far from the truth. In addition to the iron triangle, the construction industry must focus on other crucial success factors. Therefore, this study investigates the essential KPIs for construction projects in Saudi Arabia. This research employed a questionnaire survey as its major data source to determine the most critical KPIs for construction projects. The secondary data was collected from a comprehensive review of relevant literature, and the important performance indicators for construction projects in Saudi Arabia were selected and then evaluated using a questionnaire survey. The study found that the most important KPIs are Time, Cost, Quality, Safety, Sustainable Construction, Client Satisfaction, End-User Satisfaction, Risk management, Productivity of labour, and Profitability. This research adds to the corpus of knowledge on the Saudi Arabian key performance indicators for construction projects.