INTRODUCTION: Pragmatics plays a crucial role in learning and socio-emotional adaptation and it is a core area of impairment in Autism Spectrum Disorder (ASD). The aim of this study is to examine the discriminant validity of the Spanish adaptation of the Language Use Inventory (LUI-Spanish), designed to assess pragmatic skills in children. MATERIALS AND METHODS: The study included 40 children diagnosed with ASD and 40 typically developing (TD) children, aged between 24 and 42 months. The LUISpanish, a parent-report measure of pragmatic language, was used to assess communication through gestures, words and sentences. The Mann-Whitney U test was employed for group comparisons. RESULTS: Statistically significant differences were found between the ASD and TD groups in most of the LUI scales, except for Part 1 and the scales included. The TD group consistently scored higher, with large effect sizes. The instrument demonstrates both theoretical and practical relevance for assessing early pragmatic skills and guiding appropriate interventions.