Lessons conducted in hospitals ensure school continuity for hospitalized children unable to attend regular school. Hospital-based school (HS) provides a tailored experience that ensures normality for children through education. The objective of this study is to evaluate the effects of the proposed lessons in reducing negative emotions, distress, and pain in children, as well as fostering positive affects. The study was conducted with 32 hospitalized children, aged 8-12 years, in the Onco-Hematology and Pediatric Unit of Meyer Children's Hospital IRCCS (Florence, Italy). Positive and negative emotions were measured using the "Positive and Negative Affect Scale for Children"; distress was measured using the "Physiological Hyperarousal for Children"; pain was measured using the "Visual Analogue Scale" for children. Variables were assessed before (T0) and after (T1) lessons, for three times; for each variable, collected data were averaged at both T0 and T1. Statistical analyses showed a significant increase in positive emotions in hospitalized children and a significant decrease in negative emotions, distress, and pain; nevertheless, only for pain the significant correlation between its scores before and after the HS lessons indicated that the detected change occurred for all participants in much the same way. These preliminary results suggest that HS lessons can promote hospitalized children's well-being, at least as far as pain reduction is concerned.