Despite ample evidence linking particular child temperament characteristics to behavior disorders later in life, there is currently a lack of temperament measures that can be used early, easily, and widely for screening purposes. To redress this gap, the current research aimed at developing a very brief scale of child temperament characteristics that have been found to predict behavior problems over the long term, are represented across models of temperament, and have the potential to exhibit measurement invariance over different countries and childhood periods. The new scale was derived from the Integrative Child Temperament Inventory, a 30-item measure to assess five well-established temperament dimensions, and examined in three studies with samples of children aged between 2 and 8 years across five countries: The United States, the United Kingdom, China, Germany, and Spain (N = 13,425; boys 55.96%). The studies included tests of measurements invariance, of convergent validity with established measures of temperament, and of criterion validity with measures of behavior problems. The scale exhibited full metric invariance and partial scalar invariance across age groups (toddlerhood, preschool, school age) and countries. Test–retest reliability, interrater reliability across teachers, and convergent and criterion validity were adequate. Preliminary data on the measure’s clinical utility suggest a favorable balance between brevity and screening accuracy. Altogether, this study suggests that early childhood temperament characteristics placing children at risk for developing behavior problems much later in life can be quickly, effectively, and commensurably assessed across different countries and age groups.