Elevated blood pressure (BP) is a growing burden worldwide, leading to over 10 million deaths each year. May Measurement Month (MMM) is a global initiative aimed at raising awareness of high BP and to act as a temporary solution to the lack of screening programs worldwide. A World Health Organization and Ministry of Health STEPS Survey conducted in 2009 in Malawi found that 32.9% tested positive for age-standardized hypertension. The survey further showed that three-quarters (75%) of the participants never had their BP measured before and 94.9% with high BP were unaware of the hypertensive condition. 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. The screening took place in cities of Lilongwe and Blantyre mostly in hospitals, clinics, marketplaces, workplaces, and churches. About 4009 individuals were screened during MMM17. After multiple imputations, 849 (22.3%) had hypertension. Of individuals not receiving antihypertensive medication, 697 (19.1%) were found to have hypertension. Only 152 individuals were receiving antihypertensive medication, and of these 78 (51.4%) had uncontrolled BP. MMM17 was the largest BP screening campaign ever undertaken in Malawi. The results identified a large number with hypertension who were not on treatment and over half of those on antihypertensive treatment who were uncontrolled, indicating the need for better management of cases. These results suggest that opportunistic screening can identify significant numbers with raised BP.