The May Measurement Month (MMM) campaign was carried out in China in 2022 with the aim of raising awareness of raised blood pressure (BP). Here, we report the findings of the campaign. Adults aged ≥18 years were recruited opportunistically at 30 China provinces. Three seated BP readings were taken for each participant, along with completion of a questionnaire on demographics, lifestyle factors, and comorbidities. Hypertension was defined as a systolic BP ≥ 140 mmHg and/or diastolic BP ≥ 90 mmHg or being on antihypertensive medication. Controlled BP was defined as being on antihypertensive medication with a BP <140/90 mmHg. Multiple imputation was used to estimate any missing BP readings. In total, 188 975 were screened, with a mean age of 46.0 years, and 49.6% of whom were female. Of all participants, 49 788 (26.3%) had hypertension, of whom 11 268 (22.6%) were aware, and 10 945 (22.0%) were on antihypertensive medication. Of those on antihypertensive medication, 6362 (58.1%) had controlled BP, and of all participants with hypertension, 12.8% had controlled BP. After adjustment for age, sex, and use of antihypertensive medication, both systolic and diastolic BP were significantly (P ≤ 0.01) higher in those drinking alcohol 1-3 times per month (n = 24322, + 0.7/+0.4 mmHg) and higher still BPs in those drinking 1-6 times per week (n = 10691, +2.9/+1.0 mmHg) compared with those who never or rarely drank alcohol. In total, 43 426 (23.0%) were found to have either untreated or inadequately treated hypertension. The MMM campaign in China identified particularly high rates of untreated hypertension and also inadequately treated hypertension, which should inform strategies to improve the detection and management of hypertension in China.