Erroneous urine tests for sugar can result from many causes. The Clinitest method carried out in the usual recommended way (5 drops of urine) is accurate in the 0 to 2% sugar concentration range. Over 4%, there is a reversal of color which can be mistaken for 0.75 or 1% and which is referred to as "pass through." When 2 drops of urine are used instead of 5, the range of Clinitest change is extended from 0 to 5% and the "pass through" delayed until a concentration over 10% sugar is reached. In 191 urines from diabetic children, the confusing "pass through" was found to occur 70 times when the urine was tested by the "5/drop method." It did not occur in testing the same urines using the "2-drop method." Quantitative chemical analysis established the range of these 2 methods. It is recommended that the "2/drop method" should replace the "5/drop method.".