With the aim of gathering adequate in-depth information about sexual attitudes and behaviors prevailing among substance users in order to use them in the prevention of STDs, a focus group was carried out in a Substance Use Treatment Center in a governmental mental hospital in Cairo, Egypt. A group of 14 male substance users living in Greater Cairo, age range 21 to 45 years and who had been admitted to the hospital for detoxification and or rehabilitation. A trained moderator introduced the group to the main idea of the meeting and presented them with the guidelines. Two trained note-takers wrote what was going on in the meeting in detail. Descriptive themes identified in this study depict the prevailing sexual activities embodied in the experience of the substance using culture in Egypt. The themes were: a) a definite relation was present between substance use and sexual activities, especially among married persons, b) engaged unsafe sex, and c) there were no health surveillance measures considered. The findings highlighted the urgent need for health education for the substance users as well as their need to be enrolled in a health surveillance system for early detection and proper management of any possible infection among these patients and/or their relatives.