Abstract Introduction Biological rhythm is associated with the level of alertness, cognitive performance and mood of the individuals. Its regularity is essential to preserve good health and quality of life. Objective To present the steps for the construction of the scale entitled Biological Rhythm Interview of Assessment in Neuropsychiatry – Kids (BRIAN-K), designed to measure biological rhythm disruptions in Brazilian children and adolescents. Methods Items were developed following the adult version of the scale. Analysis of the psychometric characteristics of the scale was based on the responses of 373 parents/caregivers of school age children (7 and 8 years old). Results A theoretical model of 17 items with the purpose of evaluating four domains (sleep, activities, social rhythm and eating pattern) was determined using exploratory factor analysis (EFA) and via identification of a general factor. The psychometric properties of the BRIAN-K showed favorable properties. Conclusion Only two items needed to be rewritten. Further studies are needed to investigate the instrument's adequacy to different age groups and additional evidence of validity and reliability.