Keeley, Smith, and Buskist (2006) investigated the psychometric properties of the Teacher Behavior Checklist (TBC), but did not provide evidence that the measure could differentiate among teachers. This study required students at 2 schools to rate their best professor, worst professor, and most recent professor on the TBC. We found highly similar results across these schools. Differences among teachers accounted for more variability in TBC ratings than other possible sources. TBC ratings evidenced significant differences across good versus bad teachers. (Contains 2 notes and 3 tables.)