ABSTRACT This study aims to examine the reliability and validity of the Head-Toes-Knees-Shoulders Revised (HTKS-R) as a measure of self-regulation in Brazilian children aged 3–5. The early childhood period is crucial for laying the foundations for personal, social and cognitive functioning, influencing development throughout life. Self-regulation, a malleable construct, plays a vital role in academic performance and behaviors throughout life. The HTKS-R, a widely used measure, assesses behavioral self-regulation, including cognitive flexibility, working memory and inhibitory control. The study included 379 children between the ages of 3 and 5 from a variety of backgrounds. Data were collected using the HTKS-R, a standardized self-report measure that integrates executive functions into a game to assess self-regulation. Exploratory Graphical Analysis (EGA) and Confirmatory Factor Analysis (CFA) were employed to analyze the data. The results of the EGA and BootEGA indicated a unidimensional structure for the HTKS-R, confirming its internal consistency and stability. The CFA supported the fit of the unidimensional model, demonstrating the test’s construct validity. The HTKS-R showed factorial invariance between genders. The results suggest that the HTKS-R is a reliable and valid measure of self-regulation in Brazilian children aged 3–5. The applicability of the test in different age groups and environments provides valuable information about children’s self-regulation skills. The study contributes to the literature by validating the HTKS-R in the Brazilian context and highlights its potential for assessing self-regulation in diverse populations.