Background Very few studies have evaluated the quality of life (QoL) of children suffering from low-flow vascular malformations. This is the first study investigating the influencing factors.Objectives To identify the factors influencing QoL in children with low-flow vascular malformations.Methods We conducted a qualitative study employing focus group interviews (Clinical Trials Number: NCT03440827). The study was a prospective, interventional, non-comparative, multicentre study performed in four expert centres for vascular anomalies. Qualitative data about personal experiences, feelings, difficulties, needs and various factors influencing behaviours were collected. Theme-based content analysis (manual and specialist textural software guided) were used to analyse the verbatim transcripts of all focus group sessions. Manual qualitative discourse analysis was performed to identify the different themes and categories. Informatics' analyses were subsequently performed for each individual category.Results Ten focus groups (26 individuals including 10 children aged 11 to 15 years) were conducted until saturation. Influencing factors were related to 4 categories: medical care, self-image, social impat on daily activities and challenging social relationships. These factors were responsible for intrafamily upheavals and may lead to future identity-building problems.Conclusions This study provides an essential framework from which physicians can develop strategies to improve patient care and quality of life. These data may also be useful to develop specific age-sensitive QoL questionnaires.