Introduction Because of cultural and legal discrimination enacted towards LGBT people in eastern Africa, innovative methods are needed to safely engage LGBT Africans in sexual health research.

Methods We conducted two online focus groups (FGs) with eastern African MSM, one in December 2016 and the other in January 2017. Participants were recruited via Facebook advertisements, which were targeted to men who: were ‘interested in’ men or were ‘interested in’ men and women; were living in: Rwanda, Uganda, Kenya, Tanzania, or South Sudan; and were 18 years and older. People who clicked on the ad were linked to the study website, which explained the FG activity, provided an eligibility screener, and a consent form for those who were eligible. Once consented, MSM were linked to the online FG, where they could anonymously post answers.

Results After a 27 hour FB campaign, 1 76 480 people were reached across eastern Africa, 11 889 of whom clicked on the ad. Most clicks (59%) were from people in Tanzania; Kenya (22%) and Uganda (13%) were the next most common sources of clicks. Thirty-three people completed a screener and were eligible, and 22 consented to take part in the first FG. Of those who consented, 5 people posted in at least one thread in the online FG bulletin board. Of the 15 threads we posted, 3 received posts from participants, none of which were sexual health-related. To invigorate response rates, the FG script was shortened from 15 to 6 threads and displayed on one instead of three separate pages. A second 27 hour FB campaign was launched. A similar number of eligible people were identified (n=35) while more consented (n=34). One person went on to post in 4 sexual health-related threads, and another posted in one.Additional FGs are being conducted. Lessons learned that can inform future research that endeavours to engage LGBT Africans will be presented.

Conclusion Although online data collection holds promise in reaching hidden populations, piloting work is necessary to determine the most effective way to ensure privacy and promote participation.