BackgroundIn England, vaccination for human papillomavirus, hepatitis A, and hepatitis B is recommended for men who have sex with men (MSM). However, uptake is sub-optimal and some men do not complete all recommended vaccine doses. This service evaluation aimed to explore reasons for lack of uptake for each of these vaccines among MSM in one English sexual health service and to inform improvements in service delivery to increase full dose completion rates.MethodsMSM, ≥18 years, who had previously attended NHS Solent Sexual Health for at least one vaccination, and who had not completed the full dosing regimen for at least one of these vaccines, were invited to participate in an anonymous, online survey between 14/12/2020-11/04/2021.ResultsAmong 246 MSM (M= 42.1 years), the most common reason for non-vaccination was that participants thought it was unneeded and had not been recommended by a doctor or healthcare provider. None reported vaccine hesitancy. Likewise, the most common reasons for vaccination were doctor/healthcare provider recommendation (51.7–65.6%) and self-protection (60.9–68.1%). The most common reason for not having completed the full course of vaccination was being unaware that the next dose was due (30.0–37.8%). Many participants who had not completed vaccination indicated that a doctor/healthcare provider recommendation would be a motivating factor and that reminder messages and being able to book subsequent appointments in advance would facilitate vaccination.ConclusionsSexual health clinicians should be encouraged to discuss STI vaccination with MSM and services should explore possibilities to improve ease and access to vaccine appointments to increase uptake and completion rates.