The case method is a key tool that teachers can use to develop their practical knowledge and practical thinking styles in both preservice and inservice education. The case method in Japanese teacher education has been a major approach for more than 100 years. The approach to case method described here has been implemented in five settings: (1) the use of case studies in school-inhouse workshops, transforming the "theory into practice" approach into the "theory through practice" or the "practice-critique-development" approach; (2) introduction of the case method into informal study groups; (3) creation of innovative teacher inservice programs in the teacher training centers though use of the case method of instruction; (4) the use of the case method in the university preservice program; and (5) the production of case books on teaching. In the case books, the intent is to correlate the multiple interpretations of specialists with those of teachers, centering upon the practical problem-solving process in a teaching case. The case method can be a strong force that helps teachers build a professional community in Japanese schools. (IAH)