Objective: The objective was to obtain normalized data from the ADHD Rating Scale–IV–Preschool Version (ADHD-RS-IV-P) in a Spanish sample. Method: We translated and adapted the ADHD-RS-IV to our culture to obtain normalized data from a random representative sample of 1,426 Spanish preschool children (3 to <7 years old; 49.7% males). To analyze differences between evaluators, we used MANOVA. Internal consistency was assessed via Cronbach’s alpha. Results: The mean age was 4.7 years old. There was a significant sex effect. The questionnaire had an internal consistency between .86 and .96 according to subscale and evaluator. Conclusion: To evaluate ADHD in preschool children, it is necessary to use scores standardized by sex. Using a validated scale in schools and primary care centers may be useful for early detection of ADHD.