This study was designed to determine the functions of hospitalized preschool children's questions. Subjects were 24 hospitalized preschool children ranging in age from 3 years to 5 years, 11 months. Subjects' spontaneous questions, addressed to adults in a hospital setting, were recorded and categorized using Piaget's functional classification. The categories were: (a) causal explanation, (b) reality and history, (c) actions and intentions, (d) classification and evaluation, (e) rules, and (f) calculation. The frequency distribution of questions was determined by categories. The largest percentage of questions (53%) was about actions and intentions of persons, primarily hospital personnel. Small percentages dealt with classification and evaluation (13%) and reality and history (12%) Causal explanation questions (8%) were uncommon. A larger percentage of actions and intentions questions was found in the hospital than in nonstressful school settings. The findings suggest that hospitalized preschool children need orientation to the actions and intentions of personnel in regard to therapeutic activities, routine care, and play and social activity.