High blood pressure (BP) is a major risk factor for cardiovascular diseases and was identified as the most significant single preventable cause of mortality. The prevalence of hypertension in Saudi Arabia is high. To raise awareness and identify undiagnosed hypertension, the Saudi Ministry of Health participated in the May Measurement Month (MMM) 2019 global screening initiative of the International Society of Hypertension. Ninety-two primary care centres across the Kingdom recruited respondents aged ≥18 years through opportunistic sampling, from 1 May to 30 August of 2019. Data collection included sociodemographic, lifestyle habits, environmental, and anthropometric indicators. Blood pressure was measured twice using automated BP devices. A total of 25 023 adults were screened with a mean age of 42.4 (16.7) years and a mean body mass index of 27.5 (6.0) kg/m2. In total, 43.6% of participants were females and 56.4% were males. Of all the participants with hypertension, 60.8% were aware, 60.8% were on antihypertensive medication, and 39.3% had controlled BP (systolic BP <140 mmHg and diastolic BP <90 mmHg). Moreover, out of 4440 participants on antihypertensive medication, only 64.6% had controlled BP. The high numbers of individuals with hypertension and with undiagnosed hypertension highlight the importance of BP screening campaigns to increase awareness, detection, and target treatment on a national level. Findings from this study can form a baseline by which to measure progress in future iterations of MMM.