Rhetorical word stress has been identified as a feature of public, presentational, and didactic speech styles in Spanish through theoretical descriptions, intuitive accounts, and laboratory-based empirical research. Most scholars agree that non-primary stress is acoustically marked by pitch and primary stress is marked by segment lengthening. The current study offers a novel perspective by exploring naturally occurring speech of four university teaching assistants (TAs) in intermediate second language (L2) Spanish classes. From the audio data, I extracted words containing rhetorical stress and similar words containing only primary stress, then measured prosodic correlates of pitch, intensity, and duration. Two TAs produced more rhetorically stressed words than the other two, likely due to native speaker status, time teaching at the host institution, or experience teaching the course. Results from acoustic analyses support hypotheses that pitch is the main marker of rhetorical stress and duration is the main marker of primary stress. Stress clash was not avoided, and both initial and alternating stress patterns were observed. Intensity was also strengthened in rhetorically stressed syllables, indicating that intensity and pitch work together for rhetorical stress production in L2 classrooms. Evidence suggests that rhetorical stress is used by teachers to establish authority and get students' attention.