Quantitative determinations of the sensitivity to epicillin, ampicillin, penicillin and tetracycline were carried out for 67 gonococcus strains isolated from 67 males with urogenital gonorrhoea, and 38 strains isolated from 38 females with urogenital/rectal gonorrhoea. The results of the sensitivity determinations for ampicillin, penicillin and tetracycline were compared with the findings of a previous investigation. It was found that the gonococcus strains isolated from males had become slightly less sensitive to penicillin between 1971-1972 and 1976. The penicillin and tetracycline had not changed during this period. It was also striking that the in vitro activity of epicillin for strains isolated both from males and females was significantly greater than that of ampicillin.