BACKGROUND:Auscultatory mercury sphygmomanometers to measure blood pressure (BP) have been banned from health services because of risk of pollution and environmental accidents with mercury. Aneroid appliances could be an alternative. OBJECTIVE:To validate the Missouri aneroid device for blood pressure measurement in cancer patients according to the protocol of the European Society of Hypertension (ESH). METHODS:33 patients hospitalized or under outpatient care at the Cancer Institute of the State of São Paulo, FMUSP, were evaluated. Three trained and blinded observers performed nine sequential blood pressure measurements interspersed with the mercury sphygmomanometers. The differences between the values of systolic blood pressure (SBP) and diastolic blood pressure (DBP) of the test device with the mercury sphygmomanometer were classified according to the ESH protocol. RESULTS:The Missouri equipment underwent all three phases required by the ESH Protocol for SBP and DBP, and it was approved in all of the phases. The average difference between the test device and the mercury sphygmomanometer was 0.62 (SD = 4.53) and 0.06 (SD = 6.57) mmHg for SBP and DBP, respectively. No association was found between the differences in BP measurements with sex, age, body mass index and arm circumference and length. CONCLUSION:The results revealed that the aneroid Missouri device meets ESH accuracy recommendations for the measurement of SBP and DBP, and it can be used to replace the mercury sphygmomanometer.