Material and Method: The RLD questionnaire was completed by parents of 319 typically developing children, aged 18 to 30 months old. All children were referred to developmental and behavioral pediatricians. The Mullen Scales of Early Learning (Mullen, 1995) was administered to confirm the diagnosis of typically developing children and children with delayed language development.

Results: The cut-off score that best distinguished children with delayed language development and typically developing children was 8, with a sensitivity and specificity of 72.1% and 92%, respectively. The discrimination ability was good, with an area under the curve of 0.82 (95% CI 0.74 to 0.90).

Conclusion: The RLD questionnaire is a promising screening instrument for use to detect children with language development delay early during well-child care visits or at primary care centers.

Keywords: Children, Language development, Questionnaire, Screening