(1) Some data are presented concerning the frequency and potential morbidity of sexually-transmitted organisms other than T. pallidum or N. gonorrhoeae. (2) Most of the diseases with which these organisms are associated are more prevalent than syphilis and some, at least in one sex, are as common as gonorrhoea. A number appear to carry considerable morbidity, which in the case of Type II herpes virus--if it is responsible for cervical cancer--may ultimately cause more fatalities than syphilis. (3) It is concluded: (a) that, if syphilis and gonorrhoea were reduced to the point of representing no public health concern, many other sexually-transmitted conditions would still remain to pose significant problems: and (b) that health education and other methods of prevention should, where possible, be designed to take into consideration the epidemiological implications of the other organisms listed.