Introduction Understanding patients’ experiences is important when developing interventions for people living with persistent pain. Interviews and focus groups are frequently used to capture beliefs, views, and perspectives. These methods often require a commitment to a predetermined date and time that may present a barrier to participation. An asynchronous online discussion forum, specifically designed for research purposes, provides an alternative and potentially more accessible method for participation. In this article we discuss a bespoke online discussion forum, the Q-PROMPPT blog, as a case example. Methods We describe how we developed the Q-PROMPPT blog, with patient and public involvement, and its use as an innovative method for qualitative data collection in the context of developing an intervention for patients prescribed opioids for persistent pain. Drawing on our experiences we discuss the following areas: planning and design, participant recruitment and registration, and participant experience and engagement. Results We identify and address key concerns for each area of the Q-PROMPPT blog: planning and design: choosing software, assigning roles, designing the interface to promote usability; recruitment of participants: recruiting eligible participants, participant anonymity; participant experience and engagement: mitigating risk of harm, facilitating discussions, planning for forum close. Conclusion Based on our lessons learnt, we outline recommendations for using a bespoke online discussion forum as a qualitative method to inform intervention development for people living with persistent pain. These include collaboration with information communication technology teams, co-design with patient and public partners, minimising risk of imposter participants and developing trust and online community identity.