This study investigates the relationship between oral proficiency and reading proficiency in English-learning children (L2 students) and native English-speaking children (NE students). A set of oral activities measuring students' academic oral skills in science classes was developed and administered to 61 fourth graders. Both the meaning-related aspects and the formal aspects of the students' academic oral proficiency were compared between strong and struggling readers and between NE and L2 students. The study thus used a 2 x 2 factorial design (Strong/Struggling Readers x NE/L2 Students). After controlling for the students' nonverbal analytic and reasoning skills, this study found that strong and struggling readers showed different levels of performance with respect to the meaning-related aspects of oral academic language but not with respect to the formal aspects of language. Conversely, differences between NE and L2 students were found in components related to the formal aspects but not in those related to the meaning aspects of oral language. (Contains 4 tables and 1 figure.)