Elevated blood pressure (BP) is a growing burden worldwide, leading to over 10 million deaths each year. The cardiovascular mortality rate in Hungary is twice as high as the European Union average. In a recent Hungarian screening programme, among those volunteers who claimed to be healthy, BP was above 140/90 mmHg in 24% and 39% in women and men, while the control rate was 45% and 36% in women and men, respectively. May Measurement Month (MMM) is a global initiative by the International Society of Hypertension aimed at raising awareness of high BP and to act as a temporary solution to the lack of screening programmes worldwide. An opportunistic cross-sectional survey of volunteers aged ≥18 was carried out in May 2017. BP measurement, the definition of hypertension and statistical analysis followed the standard MMM protocol. In Hungary, 97 sites were set-up in primary and secondary care facilities, in pharmacies and in malls. All regions, both cities and villages were involved. A total of 3967 individuals were screened. After multiple imputation, 2052 subjects (51.8%) had hypertension. 553 (22.4%) of untreated individuals had hypertension, and 666 (44.5%) of treated individuals had uncontrolled BP. More than 50% of the screened cohort had hypertension (treated and controlled, treated and uncontrolled or untreated). By identifying almost one-third of the screened cohort with the possibility of newly diagnosed or uncontrolled hypertension, the Hungarian part of MMM17 suggest that opportunistic screening can identify significant numbers with raised BP.