Background: Implant-based breast reconstruction (IBBR) is the most commonly performed breast reconstruction technique worldwide but the technique is evolving rapidly. High-quality evidence is needed to support practice. Randomised controlled trials (RCTs) provide the best evidence but can be challenging to conduct. iBRA is a four-phased study which aimed to inform the feasibility, design and conduct of an RCT in IBBR. In phase 3, the randomisation acceptability study, an electronic survey and qualitative interviews were conducted to explore professionals' perceptions of future trials in IBBR. Findings from the interviews are presented here.Methods: Semi-structured qualitative interviews were undertaken with a purposive sample of 31 health professionals (HPs) who completed the survey to explore their attitudes to the feasibility of potential RCTs in more detail. All interviews were transcribed verbatim and data were analysed thematically using constant comparative techniques. Sampling, data collection and analysis were undertaken iteratively and concurrently until data saturation was achieved.Results: Almost all HPs acknowledged the need for better evidence to support the practice of IBBR and most identified RCTs as generating the highest-quality evidence. Despite highlighting potential challenges, most participants supported the need for an RCT in IBBR. A minority, however, were strongly opposed to a future trial. The opposition and challenges identified centred around three key themes; (i) limited understanding of pragmatic study design and the value of randomisation in minimising bias; (ii) clinician and patient equipoise and (iii) aspects of surgical culture and training that were not supportive of RCTs.(Continued on next page)