Semiquantitative methods for measurement of glucose in the urine are useful for monitoring glucose homeostasis in subjects with diabetes mellitus where quantitative blood and urine glucose measurements are not available. The use of a "plus" scale for glucose measurement is confusing because the same plus values are assigned to different quantities of glucose with different methods. The two-drop Clinitest method is the most quantifiable and readable test for urine sugar, particularly if there is high sugar spill. Therefore, it is the most useful method for monitoring insulin-dependent juvenile diabetes. Its major disadvantages are its potential toxicity, the cumbersome methodology, the cost, and the possibility of interference from other reducing substances. The enzyme "dipstick" methods are most sensitive for detecting the presence of glucose. Among the available "dipstick" methods, Diastix is the most quantifiable and readable. These methods are inhibited by the presence of ketones and a number of other substances. Tes-Tape is the least expensive and, where there are inhibiting substances, the most useful, because it can be read at the liquid front where the glucose reaction is chromatographically separated. Clinistix and Chemstrip are essentially screening methods for the presence of glucose and not useful for quantification. Basing therapy on these and other plus values is irrational and should be discontinued.