Teaching styles and possible sex-typed differences in teaching approaches were studied at Ohio State University. Classroom teaching behaviors of 167 professors were observed, and interviews with a subsample of 30 professors were conducted. Additionally, student reactions to these classroom behaviors were assessed through a questionnaire administered at the end of the term. It was hypothesized that sex differences in teaching styles exist because of the role strain and status inconsistency experienced by women professors. Fairly clear and consistent sex differences were found in three kinds of teaching behaviors: those involving (1) good teaching, (2) authority management, and (3) personalizing in the classroom. While both male and female professors were equally committed to teaching in general and both were likely to spend the majority of classroom time lecturing with a fair amount of time given to student participation, women professors seemed to take a more person-oriented, student-centered approach to teaching. They were concerned with the emotional atmosphere in the classroom, with students as total persons, and with involving students extensively in the learning process. Women's orientations were more expressive and less instrumental than the men's. This difference in orientation is clearly evident in both the interview and observational data. Although teaching styles did not appear to be strong determinants of student evaluations, differences in evaluations of male and female professors are noted. A sample student questionnaire and faculty interview schedule and references are appended. (SW)