Sixty-one gonococcal strains isolated in Greenland during 1998-1999 were tested locally for susceptibility to penicillin and ciprofloxacin by a disc diffusion method (Rosco) and at the reference laboratory in Copenhagen by the agar dilution method and the E-test, showed that more than 60% of the strains were less susceptible or resistant to penicillin (minimum inhibitory concentration [MIC] > or = 0.25 mg/L), indicating that penicillin should not be used as a first line drug for the treatment of gonorrhoea in Greenland. The Rosco disc diffusion method only identified 8% of strains as less susceptible to penicillin. Ciprofloxacin can still be used as a first line drug for treatment of gonorrhoea in Greenland since decreased susceptibility was only seen in one imported strain. However, the decreased susceptibility in this strain was not identified by the Rosco disc diffusion test, therefore the future local surveillance of antibiotic resistance in Neisseria gonorrhoeae will be based on MIC determinations.