The Phadebact Gonococcus Test (Pharmacia Diagnostics, Piscataway, N.J.) is used for the identification of Neisseria gonorrhoeae. In this test, boiled organisms are examined by using a 3-min coagglutination technique. A total of 313 isolates of Neisseria confirmed by the fluorescent-antibody technique or identified to the species level by the cysteine-tryptose agar utilization technique, were tested by the coagglutination technique. Of 229 isolates of N. gonorrhoeae, 13 (5.7%) were negative by the coagglutination technique on the first testing, 4 (1.7%) of which remained negative on subsequent testing after subculture. Of the 84 isolates of Neisseria other than N. gonorrhoeae, none showed a positive coagglutination reading. The Phadebact Gonococcus Test provides rapid, accurate identification for most isolates of N. gonorrhoeae. As with any new technique, standard procedures (fluorescent-antibody or cysteine-tryptose agar analysis or both) should be performed along with the new technique until laboratory workers are comfortable with the performance and interpretation of the test. We must, however, emphasize that it is very important to follow carefully the procedures outlined on the package insert.