Background: Many studies were conducted to assess the benefit/risk of equimolar mixture of oxygen and nitrous oxide (EMONO), but evaluating the appetite associated to its use is now getting very little attention in the literature. The purpose of this study was to investigate the effects present, felt, and sought during care by the child related with the 50% nitrous oxide/oxygen (EMONO) sedation used in pediatric dentistry. Materials and methods: All patients in consultation with the Dental Service of Nantes hospital and in need of EMONO were included in the study. In this prospective single-center study, the effects present, felt, and sought during care by the child and the assessment of EMONO appreciation were recorded. The presence of clear signs that the child was trying to extend the duration of the EMONO use was also sought. Results: Only 62% of the patients were presented with an anxiolytic effect, and 40% relative analgesia. Both effects were associated in 33% of children. Over the 76 patients assessed, 12 attempted to extend the duration of the EMONO use (16%). After a bivariate statistical analysis, none of the variables appeared significantly associated with the extension of the EMONO use duration. Conclusion: The significant proportion of patients who have prolonged the EMONO use seems to indicate a real attraction for nitrous oxide. This is the first study to evaluate nitrous oxide appreciation on a child.