Human urine specimens containing 5 different drugs [methadone, morphine, cocaine, amphetamine, secobarbital] each at 3 levels of concentration with 0-5 drugs in a specimen, were sent to 2 approved laboratories. In only 46.9% and 13.8%, respectively, were all drugs present correctly identified and no false-positive results reported. With some allowances, the results improved to 53.8% and 49.4%. If these tests are to be continued the fallibility of these tests should be known by all treatment personnel, laboratories should be licensed rather than merely approved and maintenance of the license should be made contingent on passing blind proficiency tests.