This study examined a Thai biology teacher's creative tensions when she was challenged to adopt a new teaching approach to photosynthesis with her class. The teacher was purposively selected on her need of professional growth. Data from observations and interviews documented the tensions. The data indicated that the biology teacher experienced tensions with regard to her own conceptual knowledge, in initiating teacher-student discussion and in challenging students' class participation. The teacher's prior professional experience and the researcher's additional reflection may have helped the teacher to solve these pedagogical problems.