Black men who have sex with men (BMSM) have higher HIV incidence and prevalence when compared to other MSM, despite similar levels of condom use and testing. Pre-exposure prophylaxis (PrEP) could be a useful intervention to reduce these inequalities. This research therefore aims to understand the dimensions of acceptability of a potential PrEP service for BMSM aged 18-45 years in London. In-depth semi-structured interviews were conducted with 25 PrEP-eligible BMSM between April and August 2016. Interviews were recorded and transcribed verbatim, then subject to a thematic framework analysis, informed by intersectionality theory. BMSM had distinct preferences for sexual health services, which have implications for PrEP service development. Three primary domains emerged in our analysis: proximity and anonymity; quality, efficiency and reassurance; and understanding, empathy and identity. These relate, respectively, to preferences regarding clinic location and divisions from community, features of service delivery and staff characteristics. Due to concerns about confidentiality, community-based services may not be useful for this group. Careful consideration in regards to components used in service development will facilitate ongoing engagement. Interpersonal skills of staff are central to service acceptability, particularly when staff are perceived to be from similar cultural backgrounds as their patients.