OBJECTIVES: The aim of the study was to explore and describe the reliability and validity of an instrument to measure preschool children's reactions to and coping with indoor noise at preschools or day care centres. DESIGN: Data were derived from an acoustical before and after intervention study providing repeated measurements. SETTING: The study was performed at seven preschools in Mölndal, Sweden. PARTICIPANTS: Children were recruited from these preschools and the final sample comprised 61 and 59 preschool children aged 4-5 years, with a response rate of 98% and 48% girls and 52% boys. Two children were excluded from analysis because they fell outside the age range. PRIMARY AND SECONDARY OUTCOME MEASURES: The instrument was developed based on a qualitative study performed in Swedish preschools. Questions pertained to preschool children's perception of noise when at school, their bodily and emotional reactions to it, non-specific symptoms and the coping strategies used by them to diminish the detrimental effects of the noise. RESULTS: Confirmative factor analysis yielded a three-factor model fitted to 10 items pertaining to angry reactions, symptoms and coping. The model fit was moderate to good (standardised root mean square residual=0.08, 0.12; adjusted goodness of fit=0.97/0.91) in the before and after conditions, respectively. The scales showed moderate to good reliability in terms of internal consistency, with an α ranging between 0.52 and 0.67, and was stronger in the before condition. Concurrent validity was strongest for symptoms by comparing groups based on bodily reaction (general and sound specific). CONCLUSIONS: Young children's emotional and bodily reactions to coping with noise can be reliably measured with this instrument. Like adults and older children, young children are able to distinguish between emotional reactions, bodily reactions, coping and unwell-being. Future research on larger groups of preschool children is needed to further refine the questions, in particular the questions pertaining to well-being.