The ability of a new qualitative test tablet, Microalbutest, to detect diabetics with microalbuminuria in a screening procedure was evaluated. Samples of 87 morning urines from diabetics with albumin concentrations over the range 0-200 μ/ml as well as 20 samples from healthy subjects range 1.2-12.2 μ/ml were investigated, and the results compared to measurements obtained by radioimmunoassay (RIA). For urines with RIA values above 40 μ/ml the test was positive in 96.4% with only 0.26% false negatives. Below 40 μ/ml the test results were more uncertain, an average of 30% could not be read as positive or negative. The false negative rates were 15.6% in the range 21-30 μ/ml and 4.2% in the 31-40 μ/ml range. The false positive rates were 5.7% below 10 μ/ml, 8.3% below 15 μ/ml, and 2.5% in the controls. The test was found useful as a screening method.