Arterial hypertension is a growing burden worldwide, leading to over 10.8 million deaths each year. Before the outbreak of the COVID-19 pandemic, cardiovascular diseases were the main cause of death in Ecuador. Hypertension is the main risk factor for the major cause of death, coronary and cerebrovascular disease. The 2021 May Measurement Month Campaign (MMM21) is a global initiative by the International Society of Hypertension aimed at raising awareness of high blood pressure (BP) and to provide a temporary solution for opportunistic screening until more systematic approaches can be established. A cross-sectional survey was carried out in May 2021 across 22 health centres in Ecuador. The average age of participants was 44.7 ± 15.8 years. Blood pressure measurement, the definition of hypertension (mean of the 2nd and 3rd BP measurements ≥ 140/90 mmHg or on medication for high BP), and statistical analysis followed the standard MMM protocol. In total, 1326 volunteers participated in MMM21. After multiple imputation of missing BP readings, 423 (31.9%) had hypertension. Of those, 70.5% were receiving antihypertensive medication. Of individuals receiving antihypertensive medication, 50.0% had uncontrolled BP. Overall, of 423 participants with hypertension, only 35.2% had their BP controlled (<140/90 mmHg). MMM21 demonstrated a high prevalence of hypertension in Ecuador during the COVID-19 pandemic. It was the largest BP screening campaign done in Ecuador thus far. The high percentage of persons untreated or with uncontrolled hypertension while on pharmacologic treatment suggests that appropriate screening can help to identify a significant number of people with elevated BP and those inadequately treated. These data should attract the attention of doctors and health care providers in Ecuador.