BACKGROUND: The twice-yearly, long-acting lenacapavir (LA LEN) antiretroviral therapy (ART), when combined with an optimised background regimen, provides a subcutaneous injectable treatment option for people with HIV. This study aimed to understand the preferences, barriers and facilitators for uptake and implementation of LA LEN, with a view to informing clinical implementation. METHODS: In-depth qualitative interviews and focus groups with purposively sampled people with HIV and healthcare workers (HCWs) from UK HIV services were conducted. Transcripts were analysed using summative and conventional content analysis. RESULTS: Thirty-four people with HIV with varied ART experience were recruited from two HIV services. Participants included 22 (65%) identifying as cisgender men and 12 (35%) identifying as cisgender women; median age was 55 years (range 26-76 years). Fourteen HIV HCWs took part in three focus groups. Four key themes and 12 subthemes were identified: LA LEN as a treatment option; LA LEN versus oral ART; switching considerations; and administration of LA LEN. The majority (88%) of people with HIV were interested in switching to LA LEN if offered. Preference was markedly reduced if an oral ART pairing was required. Convenience of the dosing schedule, reduced pill burden and issues around stigma were reasons for interest in LA LEN, but concerns regarding efficacy, dosing interval windows, monitoring and side effects were described. HCWs felt the benefit of LA LEN was as a treatment option for those with adherence issues, drug resistance and a high pill burden. Broader use of LA LEN raised concerns over drug resistance, delivery capacity and storage. CONCLUSIONS: LA LEN was viewed as a preferable treatment choice for many people with HIV, provided an all-injectable regimen was available. Feasibility assessments for provision of injectable ART and research on its potential for self-administration are needed.