We reviewed the results of clinical examinations conducted on and antimicrobial susceptibilities to Neisseria gonorrhoeae isolated from 51 patients with gonococcal urethritis who visited our hospital during the period from February 2005 to April 2006. The type of sexual activity by which the bacteria was transmitted was oral sex in 81.6% (40/49) of the patients, and none of the patients used a condom during oral sex. Fifty percent (24/48) of the patients were aware of the risk of getting sexually transmitted diseases (STDs) from having oral sex without the use of a condom. The ratios of drug-resistant N. gonorrhoeae were 56.9% for Penicillin G, 0% for CVA/Amoxicillin, Azithromycin and Minocycline, 5.9% for Cefpodoxime, 2.0% for Ceftriaxone, 0% for Cefodizime, and 84.4% for Ciprofloxacin, Levofloxacin and Gatifloxacin. The bacteria in 7.8% of the cases were beta-lactamase-producing strains. The results of this study indicated that STD from oral sex is prevalent in Sapporo. Increasing resistance to Quinolone was noted, but levels of susceptibility to other drugs remained relatively high.