This study examined teaching assistant's immediacy in lecture/laboratory and self-contained classes. Two hundred fifty-six students responded to instruments measuring teachers' immediacy behavior frequency, perceptions of instruction quality, and cognitive learning. No significant difference was identified when comparing lecture/laboratory and self-contained teaching assistants' immediacy behaviors. But all students who observed frequent immediate behaviors demonstrated higher affective and cognitive learning. Teaching assistants' ratings had significantly higher levels of faculty-student interaction for self-contained sections but lecture/laboratory sections were significantly higher for student effort/involvement.