Olesia Trofymenko, national coordinator of the project “Biobehavioral research among men who have sex with men in Ukraine”, attended the panel discussion “Hello, HIV: changes in prevention and needs of MSM”, which took place on September 17, 2021 Kyiv, President Hotel Kyiv. Ivan Titar, Chief Research Specialist of the Center for Public Health of the Ministry of Health of Ukraine, made a presentation on “Biological Behavioral Research Methodology for Estimating the Number Among Men Having Sex with Men 2021”. The presentation describes in detail the research methods “Biobehavioral research among MSM in Ukraine”, which is now being implemented in 16 regions of Ukraine.