Dual language learners are often underidentified for having language delays and may not receive services in their caregiver’s primary language. This study explored how the language used during evaluations influenced the effectiveness of a brief intervention for children with mild language delays. By examining whether evaluation language impacts intervention outcomes, the study provides insight into optimizing strategies for supporting children with early language challenges. Participants were 433 children (Mage = 31.12 months), who spoke English, Spanish, or are dual language English-Spanish learners who completed a brief speech-language intervention and pre- and post-intervention evaluations. We determined language “match” if the caregiver’s primary language used in the home was the same as the language in which the child received the pre-intervention baseline evaluation. Dyads were a “non-match” if the caregiver’s primary language used in the home was not the same as the language in which the child received the pre-intervention baseline evaluation. Children who had their evaluation conducted in the language that matched their caregiver’s primary language showed more improvements than children whose evaluations did not match their primary language. This study builds on previous findings on the importance of providing dual language evaluations and interventions for children with early language delays.