BACKGROUND: Few studies have looked at how decisions are made to withhold or to withdraw potentially life-sustaining treatments (LST) in paediatric nephrology. The aim of this work was to evaluate such practices in all nephrology centres in French-speaking European countries, so that guidelines could be discussed and drawn up by professionals. METHODS: We used semi-directed interviews to question health care professionals prospectively. We also retrospectively analysed the medical files of all children (n = 50) for whom a decision to withhold or to withdraw LST had been made in the last 5 years. The doctors (n = 31) who had been involved in the decision-making process were interviewed. RESULTS: All 31 of the French-speaking paediatric nephrology centres in Europe were included in this study. Of these, 18 had made decisions in the previous 5 years about withholding or withdrawing LST. Resultant quality of life, based on long-term living conditions, was the principal criterion used to make the decisions. Relational aspects of life and the child's prognosis were also considered. The decision-making processes were not always collective, even though interactions between doctors and the rest of the medical team seemed to be key elements to them. The parents' involvement in the decision-making process differed between centres. CONCLUSIONS: The criteria used to decide whether to withhold or to withdraw LST are not standardized, and no specific guidelines exist.