Background: Few treatments exist for adolescents living with severe obesity. This qualitative study explored the experiences of severely obese adolescents and their families who participated in the BOB study. Methods: Twelve adolescents (5 males; 7 females; mean age 15 years; BMI> 3.5 s.d; puberty stage 4 +) who were engaged with the research study BOB (a non-randomised, pilot novel obesity treatment programme that involved the insertion of an intra-gastric balloon coupled with a family lifestyle behavioural support programme). Adolescents attended weekly lifestyle sessions before, during and post balloon insertion. All participants were interviewed at 3 months, (halfway through intra-gastric balloon insertion) and at 12 months follow-up (6 months post intra-gastric balloon removal, 3 months post lifestyle intervention). Results: All BOB participants had exhausted all treatment options deeming this study their final option. Many alluded to feelings of desperation and referred to a sense of hope that this intervention would be effective. Family involvement and attendance within the structured sessions differed significantly. Adolescents and parents perceived support from the research study ceased when the intra-gastric balloon was removed at 6-months despite attendance post balloon removal being poor. All participants emphasised a need for further support longer term with the integration of the family a critical factor. Conclusions: Further research is needed to explore the specific role families play within treatment to optimise health and wellbeing outcomes. Adolescents perspectives should be integrated within treatment to inform and improve the effectiveness of future treatment programmes for severely obese adolescents and their families.