SummaryBackgroundAvailability of data to assess the population health and provision and quality of health care in Saudi Arabia has been lacking. In 2010, Saudi Arabia began a major investment and transformation programme in the health-care sector. Here we assess the impact of this investment era on mortality, health loss, risk factors, and health-care services in the country.MethodsWe used results of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 to describe the levels and temporal patterns in deaths, health loss, risk factors, and health-care access and quality in the Saudi Arabian population during 1990–2010 (before the health-care investments and reform) and 2010–17 (during health-care investments and reform). We also compared patterns in health outcomes between these periods with those in the north Africa and the Middle East GBD region and the Gulf Cooperation Council countries.FindingsAge-standardised mortality in Saudi Arabia decreased from 1990 to 2010 (annualised rate of change of −0·58%), and this decrease was further accelerated from 2010 to 2017 (–2·20%). The north Africa and the Middle East GBD region also had decreases in mortality during these periods, but for 2010–17 the decrease was not as low as in Saudi Arabia (–1·29%). Transport injuries decreased from third ranked cause of disability-adjusted life-years in 2010 to fifth ranked cause in 2017 in Saudi Arabia, below cardiovascular diseases (ranked first) and musculoskeletal disorders (ranked second). Years lived with disability (YLDs) due to mental disorders, substance use disorders, neoplasms, and neurological disorders consistently increased over the periods 1990–2010 and 2010–17. Between 1990 and 2017, attributable YLDs due to metabolic, behavioural, and environmental or occupational risk factors remained almost unchanged in Saudi Arabia, with high body-mass index, high fasting plasma glucose concentration, and drug use increasing across all age groups. Health-care Access and Quality (HAQ) Index levels increased in Saudi Arabia during this period with similar patterns to the rest of the Gulf Cooperation Council countries and the north Africa and the Middle East GBD region.InterpretationDecreases in mortality continued at greater rates in Saudi Arabia during the period of 2010–17 than in 1990–2010. HAQ Index levels have also improved. Public health policy makers in Saudi Arabia need to increase efforts to address preventable risk factors that are major contributors to the burden of ill health and disability.FundingBill & Melinda Gates Foundation.