Action research has established itself as a methodology in teacher education (Altrichter & Posch 1998, Burbank & Kauchat, 2003, Elliot, 1981, Liston & Zeichner, 1999, Schön 1983). The author is engaged in European project EUDIST (Lang, 2003) using action research to enhance professional development of science teachers. The EUDIST approach is based on what is called a "Curriculum Workshop" (Mulder & Thijsen, 1990). This is a discursive approach to school improvement and curriculum development with teachers as central agents. It involves structured meetings and collaboration of teachers, teacher educators and researchers in schools with the aim of developing a curriculum document for educational planning (Lang & Elster 2004). The philosophical background of the CW is educational deliberation and ethical reflection emphasising a potential of emancipation and innovation in education. Central of a Curriculum Workshop is a procedure where discursive rules (Oser, 1992) and rules of group- dynamics and interaction (Cohn, 1999) are fixed. The goal of the CW is to empower teachers (teacher teams) to initiate a school-based development for innovative science teaching in their schools. In Austria a network of four schools from Vienna conducted a series of sessions in the form of a Curriculum Workshop (CW) They exchanged experiences of innovative science teaching and specified standards for science subjects at upper secondary level. The CW was divided in three parts of two days duration each. Teachers in interdisciplinary school teams, teachers in charge of teacher education at the local teacher training center (PI) and researchers and teacher trainers of the project IMST2 (Krainer & Kühnelt ,. 2002) at the University of Vienna were involved in this collaborative curriculum project. Specific to the Austrian EUDIST project were the use of methods and instruments of action research. Elliot (1981) has shown, that the professional development of teachers is depending on their culture of reflection about their own work. Action research is expected to support teachers to establish a research relationship to their own practice. It should increase their professional knowledge, enhance the effectiveness of teaching and learning and broaden their autonomous scope. It should empower teachers as "reflective practitioners" to develop their "tacit knowledge" (knowledge in action) by "reflection on action" (Schön 1983). References: Altrichter, H. / Posch, P.(1998): Lehrer erforschen ihren Unterricht - Eine Einführung in die Aktionsforschung. Klinkhardt: Bad Heilbrunn, 3. Aufl. Burbank, M.D., Kauchak, D. (2003): An alternative model for professional development: investifations into effective collaboration. Teaching and Teacher Education 19(5), 499- 514 Cohn, R. (1990) From psychoanalysis to theme oriented interaction. Stuttgart: Klett Elliot, J.(1981): Action research. A framework for self- evaluation in schools. TIQL-Working paper No.1 Institute of Education: Cambridge Krainer, K., Kühnelt, H.(Hg) (2002): Lernen im Aufbruch: Mathematik und Naturwissenschaften. Pilotprojekt IMST². Studienverlag: Innsbruck, Wien, Münschen, Bozen. Lang, M., Hansen, K.H., Bünder, W., Klinger, U., Pinto, R., Couso, D., Elster, D., Kühnelt, H., Szbek, P.& Nott, M. (2003) Developing Best Practices for School-Based Teacher Education. Utrecht: ESERA paper. Lang, M., Elster, D. (2004): Planning school-based collaborative teaching in a discourse across subjects. Lublin: IOSTE paper Liston, D.P., Zeichner, K.M. (1990) Reflective teaching in action research in pre-service teacher education. Journal of Education for Teaching 16(3), 235-255 Mulder, M. & Thijsen, A. (1990) Decision making in curriculum conferences: a study of convergence of opinion. Journal of Curriculum Studies 22 (49) pp. 343-360. Oser, F. (1992): Morality in professional action: A discourse approach for teaching. 109-125. Oser F., Dick, A. & Party, J. (Eds.) Effectiv and responsible teaching. San Francisco: Jossey:Bass Schön, D.A. (1983): The reflective practitioner. Temple Smith: London