OBJECTIVES As medical care evolves, automated sphygmomanometers must be able to provide accurate and timely blood pressure (BP) data to the healthcare provider. We evaluated the performance of a new hand-held, battery-operated device, the Welch Allyn ProBP 3400, to the AAMI SP 10 criteria. We also performed British Hypertension Society data analysis. METHODS A total of 111 (97 adults, 14 children) participants were tested using blinded and paired observers performing auscultation of Korotkoff (K1 and K5) sounds. RESULTS Ninety-two participants had acceptable data, giving 275 paired data sets for systolic BP (SBP) and diastolic BP (DBP) analyses. The mean ± standard deviation of the observer/device differences were -1.1 ± 7.5 mmHg for SBP and -2.1 ± 6.0 mmHg for DBP. These passed the AAMI SP10 requirements. The ProBP 3400 achieved an A grade for both SBP and DBP. CONCLUSION The ProBP 3400 passed the AAMI standard requirements and achieved A grade for both SBP and DBP. The device is less in cost and completely portable. It transmits BP data directly into the electronic medical record using a Universal Serial Bus connection. These features will improve the efficiency and accuracy of BP data available to clinicians, thus improving the quality of care.