Families of children with life-limiting conditions who are on long-term assisted ventilation need to undertake end-of-life advance care planning (ACP) in order to align their goals and values with the inevitability of their child's condition and the risks it entails. To discuss how best to conduct ACP in this population, we performed a retrospective analysis of end-of-life discussions involving our deceased ventilator-assisted patients between 1987 and 2009. A total of 34 (72 percent) of 47 study patients were the subject of these discussions; many discussions occurred after acute deterioration. They resulted in directives to forgo or limit interventions for 21 children (45 percent). We surmise that many families were hesitant to discuss end-of-life issues during periods of relative stability. By offering anticipatory guidance and encouraging contemplation of patients' goals both in times of stability and during worsening illness, health care providers can better engage patients' families in ACP. As the child's condition progresses, the emphasis can be recalibrated. How families respond to such encouragement can also serve as a gauge of their willingness to pursue ACP.