The antimicrobial susceptibility of gonococci isolated in Singapore has been studied over several years. In 1983, the prevalence of penicillinase producing Neisseria gonorrhoeae (PPNG) was 33.5% and 64% of non-PPNG isolates had minimum inhibitory concentrations (MICs) of penicillin of greater than or equal to 0.5 mg/l. After a control programme, the isolation of the gonococcus from prostitutes was reduced and there was improvement in its susceptibility to antimicrobials. The incidence of PPNG strains was stabilised with a change in the treatment regimen. An influx of foreign prostitutes, however, had an unfavourable impact on these variables. Countries in South East Asia have a high prevalence of PPNG and non-PPNG strains that have reduced susceptibility to antimicrobials. In view of increased air travel the problem should be seen from a global perspective. Better treatment regimens and control strategies are urgently needed.