This study examines the beliefs about effective teaching in student teachers and inservice teachers. We constructed a measurement composed of an adaptation in Spanish of the Gibson and Dembo's (1984. Teacher efficacy: A construct validation. "Journal of Educational Psychology", 76, 569-582). Teacher Efficacy Scale and of the items included in Emmer and Hickman's (1991. Teacher efficacy in classroom management and discipline. "Educational and Psychological Measurement", 51, 755-765) ''classroom management/discipline efficacy'' dimension. A total of 339 participants took part in the study. The factor analysis carried out of the results obtained showed three principal factors: classroom management/discipline efficacy, personal teaching efficacy and general teaching efficacy. Analyses which compared efficacy expectancies showed significant differences in the management and discipline dimension in favour of the group of working teachers, whereas an opposite pattern emerged in the general teaching dimension. In addition, there were differences in the management/discipline dimension in terms of the number of years' experience in the group of inservice teachers. The interpretation of the results is expressed in terms of the Bandura's perceived self-efficacy theory. We also indicate some implications that the analysis of these expectancies may have for the training and professional development of teachers, and we suggest lines for future research.