The current drug situation in Russia and St. Petersburg is characterized by an active expansion of new psychoactive substances on the illegal market. In order to identify and specify actual risk factors for the spread of HIV infection in the group of users of synthetic cathinones ("bath salts") in the current drug situation in St. Petersburg, thirty interviews and two focus groups were conducted with users of psychoactive stimulants (synthetic cathinones). Thematic analysis of the collected data was carried out using OpenCode 4.0 qualitative data analysis software. The results of the study demonstrated changes in behavior of drug users with different experience of injecting psychoactive substances. Of significant epidemiological value were data on the transition to synthetic cathinones (“bath salts”) of the “older” generation of opioid drug users, as well as engagement in more risky behaviors of the target group when using “salts”. At the same time, there was a tendency to transition to injection use of synthetic stimulants in the "new generation" of drug users as an experience of drug abuse increased. The revealed behavioral features of synthetic cathinone users indicate that they have actual risks of HIV infection, both injecting and sexual. The data obtained in this study may be useful for specialists working in the field of HIV prevention among drug users.