This study aims to validate blood pressure (BP) values measured by an oscillometric BP monitor and seek possible calibration methods if discrepancies exist. Noninvasive BP measurement outcomes were determined using an oscillometric BP monitor (Omron HBP-1300) versus a mercury sphygmomanometer (standard device). Two percent of subjects enrolled in an epidemiological investigation were systematically sampled in this study. Intraclass correlation coefficient (ICC) was used to evaluate measurement reliability, paired t-test was used to evaluate trueness, and linear regression was used for calibration. The Association for the Advancement of Medical Instrumentation (AAMI) standards and British Hypertension Society (BHS) protocols were used for validation quality assessment. Both mercury sphygmomanometer (standard device) and oscillometric BP monitor (test device) displayed high reliability. A significant difference in systolic blood pressure (SBP) was observed between devices. SBP calibration was achieved by using an effective linear regression model (B = 0.803 and constant = 19.592, P < 0.001). The calibrated model was corroborated by verification samples (P = 0.120) and was found to pass AAMI standards and BHS protocol requirements. Calibrated SBP measurements from the Omron HBP-1300 device were valid. Use of a combination of statistical methods, such as ICC for reliability assessment as well as paired t-test for trueness evaluation can be used to validate data from the oscillometric BP monitors.