We surveyed the rate of chlamydial and gonococcal infections among human immunodeficiency virus (HIV)-seropositive patients in Thailand as well as the current status of antimicrobial resistance of Neisseria gonorrhoeae and determined the prevalence of penicillinase-producing N. gonorrhoeae (PPNG) in Thailand. A total of 1,158 endocervical swabs from 824 HIV-seropositive patients were collected to detect both organisms by Gen-Probe. The prevalences of chlamydial and gonococcal infection were 9.7 and 1.3%, respectively. Susceptibility of 122 gonococcal isolates to 6 drugs was determined by the disk diffusion method. None of the isolates was susceptible to penicillin or tetracycline. With respect to fluoroquinolones, more than 90% of the isolates were resistant to ciprofloxacin and ofloxacin. No gonococcal isolate with resistance to cefotaxime and ceftriaxone was detected. Among the 122 isolates, 83.6% or 102 isolates were PPNG, and most (79.5%) of these 122 isolates were further identified as PPNG plus tetracycline-resistant N. gonorrhoeae, with only 4.1% being PPNG alone. All of the 102 isolates identified as PPNG contained the bla(TEM) gene. We then performed a preliminary molecular study and identified, for the first time in Thailand, a PPNG isolate producing beta-lactamase and containing the bla(TEM) gene which was identical to the beta-lactamase TEM protein of Salmonella enterica identified as TEM-135.