This study examined children’s performance on the Stroop-like animal size test and its relations to parent-reported temperamental effortful control, personality, and common emotional and behavioral problems in a Russian sample of 5-12-year-olds (N = 202). The animal size test demonstrated a Stroop-like effect for accuracy and response time (RT) in both genders and across all ages. Children’s performance on the animal size test considerably improved with age such that older children performed more accurately, were faster and their responses were less variable than younger children’s responses. The findings indicated that RT was negatively related to temperamental trait of effortful control and its key components, attention focusing and inhibitory control, whereas RT variability was negatively related to both regulatory traits, effortful control and conscientiousness, and their components. Children’s performance on the AST was meaningfully related to hyperactivity-inattention, externalizing behavior and overall level of childhood psychopathology. These findings provide support for the usefulness of the animal size test in the neuropsychological assessment of preschool and school-age children.