INTRODUCTION: In shared decision-making (SDM) clinicians and patients arrive at a joint treatment decision, by incorporating best available evidence and the patients’ personal values and preferences. Little is known about the role of SDM in (paediatric) plastic surgery. For patients with congenital vascular malformations, many therapeutic options exist, ranging from surgery to compression stockings, each with different benefits and harms. Preference-sensitive treatment decision-making seems obvious, however, it has never been explored whether patients desire SDM and to what extent SDM is already practiced. Therefore, we investigated preferences regarding decision-making and current SDM behaviour during physician-patient encounters in this patient cohort. MATERIALS AND METHODS: In two Dutch university hospitals, adults and children with congenital vascular malformations facing a treatment-related decision were enrolled. Before the consultation, patients (or parents of children) expressed their preference regarding decision-making (Control Preferences Scale; CPS). Afterwards, participants completed SDM-specific questionnaires (SDM-Q-9, CollaboRATE and satisfaction), physicians completed the SDM-Q-Doc questionnaire. Consultations were audiotaped and patient involvement was scored by 2 independent researchers, using the Observing Patient Involvement (OPTION-5) instrument. All questionnaire results were expressed on a scale of 0 to 100 (optimum SDM). RESULTS: Fifty-five participants (24 parents and 31 adult patients) were included. Two-thirds preferred the SDM-approach (CPS). Objective OPTION-5 scores were low (mean 31 SD 15), whereas patient and physician SDM-Q scores were moderately high; means 68 (SD 18) and 68 (SD 19), respectively. The median CollaboRATE score was 93. There was no clear relationship between SDM and satisfaction scores. CONCLUSIONS: Although adults and parents of children with vascular malformations express a strong desire for SDM, objective SDM-behaviour is still lacking, most likely due to poor awareness of the SDM-concept among parents, patients and physicians. To improve SDM-practice in (paediatric) plastic surgery, targeted interventions (like decision aids, staff training) are essential.