The current study examined how immediacy behaviors of college professors influence student participation. While these claims have been studied in the past, this investigation examined a cross-disciplinary sample and employed a more objective methodology, classroom observation. It was hypothesized that professors who showed greater immediacy would have higher levels of classroom participation. Results indicated that teachers who were more immediate had both greater frequency and breadth of classroom participation. More specifically, warmth of the professor (a composite of four immediacy behaviors) was a primary factor in explaining student participation. Limitations, pedagogical implications, and future directions in immediacy research are discussed.