Purpose: The purpose of this study was to investigate the effects of a vocabulary intervention delivered by teachers collaborating with speech-language pathologists (SLPs) in the classroom as compared with teachers in a noncollaborating condition. Method: This quasi-experimental study employed a collaboration treatment condition (n = 2 collaborative pairs, n = 34 students) and a comparison condition (n = 2 noncollaborating teachers, n = 34 students). In both conditions, versions of the Vocabulary Scenario Technique were implemented. Third-grade students completed vocabulary assessments for three vocabulary tasks. Results on each of the measures were analyzed using a two-factor split-plot analysis of variance. Results: A significant interaction effect on the Words-in-Context (WIC) task, with a medium effect size (f = 0.28), supported the value-added impact of having the SLP collaborate directly with the teacher in implementing the approach. Gains on the Synonyms and Non-Example measures were not significantly different between the conditions, but large effects were found for all three tasks within the collaboration condition, whereas gains in the comparison condition showed large effects for the Synonyms task only and medium effects for the WIC and Non-Example tasks. Conclusions: SLPs' contributions within their collaborations were associated with gains that were larger than those made by students in classrooms where teachers did not collaborate with SLPs on a vocabulary task requiring application of word meanings in sentences. Clinical implications and areas for future research are discussed.