Teachers are exposed to many varieties of inservice education throughout their careers. It is critical to evaluate the success of such programs. One criterion of success must be the degree to which teachers effectively implement what they have learned. This study examined the effects of an inservice education program emphasizing problem solving on teacher attitudes toward teaching science and on teaching behaviors. Twenty-two middle school science teachers participated in the program and another 22 served as the control group. Before and after the 10-month project, subjects completed attitude surveys and recorded videotapes of themselves teaching science lessons. No difference was noted between the groups on the attitude measure, "The Science Teaching Attitude Scales." A MANOVA performed on the observational data showed a significant difference between the groups, with a greater difference noted after the workshop than before. The experimental teachers appeared to be shifting to more student-centered classrooms. Teachers substantially decreased the percentage of time spent on lecture and procedural talk and increased the time spent observing and listening to students. This study provides evidence that an extended inservice education program can affect the teaching behaviors of science teachers in the middle grades. References and tables are included. (MVL)