According to the literature, in the 1980s the intended science curriculum exhibited a worldwide movement toward a curriculum for all, with a more contextually embedded approach. In writings about science teaching pedagogy, a trend can be observed to consider seriously students' conceptions, based on the premises of constructivism. This article examines consequences of these trends for teacher behavior and concludes that classes should become more student centered. In terms of the model for interpersonal teacher behavior (Wubbels & Levy, 1993), teachers must give their students more responsibility and act in a more understanding way. It is to be expected that teachers' beliefs and opinions have to change before this trend can be implemented in the classroom. We have therefore tested whether teachers' opinions about objectives and content of physics education, on the one hand, and the implemented curriculum, particularly teachers' interpersonal behavior, on the other, display the same trend observed in the intended curriculum. In 1984 and 1993, data on students' perceptions of their teachers' behavior were gathered from ninth-grade students of a random sample of Dutch physics teachers. Data on the teachers' self-perceptions of their behavior and their opinions about physics education also were included. The results show that teachers were more in favor of realistic teaching content in 1993 than in 1984, a shift that is in line with the trend in the intended curriculum. Students' perceptions indicated clearly that Dutch teachers behaved less dominantly and more cooperatively in 1993 than in 1984.