A questionnaire investigation to which 144 homosexual persons replied anonomously revealed alterations in the sexual habits after information about AIDS. Significant reduction in the annual number of partners and significantly fewer employ the more dangerous sexual practices which now occur particularly in more permanent partnerships are among the alterations started. An unchanged number still employ active anal and orogenital coitus. Employment of condoms has increased significantly, particularly in anal coitus and "casual" partners (from 3% to 82%). The majority accept the use of condoms and state that they employ more "safe sex" than prior to information about AIDS. 12% stated that they had sex with both sexes and the possibility of spread of infection from homosexual to heterosexual groups is present. The intensive informative work from the homosexuals own organisation and from public health authorities appear to have had some effect but further information and influencing are necessary if the spread of HIV infection is to be stopped.