A scheme was designed to speed identification of 50 nonfermentative gram-negative bacteria to genus, species and biotype using a minimal number of biochemical tests. When the scheme was evaluated in the laboratory, 1 technologist identified 93.6% of 188 known isolates (46 species). Later another technologist, given 161 of the same isolates (46 species) as unknowns, identified 91.9%. The isolates that were misidentified in both cases were atypical organisms with aberrant biochemical reactions, plus 1 typical organism with a delayed oxidation of glucose.