This study investigated certified teachers' performance at SMPN 6 Luwuk of Banggai Regency, with a focus on the teachers' performance in planning the lesson, implementing the lesson, and conducting the lesson evaluation. It lasted for nine months, from March to December 2011. Qualitative method was used. More specifically, the evaluation research method was followed which involves collecting, analyzing, and interpreting data for decision making. The evaluation system used in this study was based on the quality of the certified teachers' performances. The real condition in the field is that many of the certified teachers are still unable to design lessons and implement them professionally as expected from certified teachers. Currently there are many teachers in need of trainings. This study showed that the quality of the performance of the certified teachers in SMPN 6 Luwuk in planning the lesson was low. This could indicate that the certification process has not yet resulted in an increase in the quality of performance of the certified teachers, particularly as long as the quality of their performance in planning lessons is concerned.