Background: The use of analgesics and sedatives to alleviate pain and discomfort is common in end-of-life care in neonates and infants. However, to what extent those drugs are used in that context with the specific aim of bringing the infant in a state of continuous deep sedation (CDS) is currently unknown. Methods: We performed a nationwide mortality follow-back survey based on all deaths under the age of 1 over a period of 16 months in Flanders, Belgium. Data on CDS were linked to sociodemographic information from death certificates. Physicians completed an anonymous questionnaire. Questions measured whether CDS preceded death, and which clinical characteristics were associated with the sedation (e.g., type of drugs used and the duration of sedation). Results: The response rate was 83% (229/276). In 39% of all deceased neonates and infants, death was preceded by CDS. Physicians used a combination of morphine and benzodiazepines in 53%, or morphine alone in 45% of all sedation cases in order to continuously and deeply sedate the infant. In 89% of cases, death occurred within 1 week after sedation was begun, and in 92% of cases, artificial nutrition and hydration were administered until death. In 49% of cases there was no intention to hasten death, and in 40% of cases, the possibility of hastening was taken into account. Conclusions: CDS precedes about 2 in 5 neonatal and infant deaths. Guidelines for CDS in this age group are non-existent and it is unclear whether the same recommendations as in the adult population apply and can be considered a good practice.