We tested the performance of the LAM 100 (also known as the Marshall F-88), a semiautomated oscillometric device for discontinuous BP measurement at the finger, which could be very suitable for self-recording of BP because of its small size and convenient mode of operation. The LAM 100 was compared with the random zero sphygmomanometer and with BP measured by the Finapres for beat-to-beat measurement of finger arterial pressure in 40 patients following guidelines of the AAMI. Compared with the random zero sphygmomanometer the LAM 100 underestimated SBP by 9 mmHg (SD 12) and DBP by 7 mmHg (SD 9). These differences exceed the limits set by the AAMI. The differences between the LAM 100 and the random zero spghymomanometer could not be explained by physiological peripheral pulse wave changes because Finapres SBP was underestimated by 4 mmHg (SD 15) and DBP was overestimated by the LAM 100 by 8 mmHg (SD 10). We conclude that the LAM 100 is not suitable for the diagnosis and management of hypertension.