1. The accuracy of the Remler M2000, a semiautomatic portable blood pressure recorder, was assessed with the London School of Hygiene (LSH) and Hawkesley random-zero sphygmomanometers used as reference standards.
2. The Remler gave higher recordings than the LSH sphygmomanometer, the mean systolic and diastolic differences being 5.9 mmHg (P < 0.001) and 4.7 mmHg (P < 0.001) respectively. No significant difference was demonstrated between paired Remler and Hawkesley recordings.
3. When simultaneous paired LSH and Hawkesley sphygmomanometer recordings were compared, the LSH gave lower blood pressures: 7.1 mmHg (P < 0.001) for systolic and 3.6 mmHg (P < 0.001) for diastolic recordings.
4. The LSH sphygmomanometer underestimates blood pressure, partly due to a calibration error but also because the selection of end points for this device differs from other methods of blood pressure measurement.