<p>This study explored relations between children’s performance during the Trier Social Stress Test for Children (TSST-C) and their cognitive and motor development. Public speaking and arithmetic portions of the TSST-C were coded for 860 and 815 Chilean 10-year-olds, respectively, and compared to their standardized cognitive and motor test scores. Linear effects indicated better cognitive and motor abilities with ratings of less nervousness and better coherency, ideas and development, and organization in the public speaking portion, and more mental arithmetic success in the arithmetic portion. To our knowledge, no previous studies have assessed the relations between performance during the TSST-C and children’s cognitive and motor function. Such relations are important, as they might influence biological responses to this widely used stress paradigm.  </p>