Four battery-operated blood glucose reflectance meters have been tested for precision, accuracy, and convenience of use. Parallel assays on 50 venous blood samples comparing a meter and a glucose oxidase reference method gave the following regression line parameters and correlation coefficients: Diatron Easytest (Eastlords Electronics Ltd), y = 0.76x + 1.23, r = 0.93; Glucochek II (Medistron Ltd), y = 0.90x - 0.01, r = 0.98; Hypocount MX (Hypoguard Ltd), y = 0.97x - 0.14, r = 0.98; Reflolux (Boehringer Mannheim GmbH). y = 0.97x + 0.18, r = 0.99. Reflolux has to be recalibrated with a barcoded film strip for each new test strip tin and is the most precise and accurate meter. Glucochek II using both whole and half BM Test Glycemie 20-800R test strips, showed similarly good precision, and was the simplest meter to use containing only one moving operational part. Hypocount MX is the smallest of these meters, is easy to use and has a memory which can store up to 10 blood glucose readings. The memory of the Diatron Easytest is bigger and easier to use since it stores and automatically updates 25 successive glucose values; however, this was the least accurate and least precise of the meters.