Constructivist instruction has been implemented in the current instructional innovation in Singapore. Large scale survey study was conducted to examine the roles of teacher efficacy in implementing the innovative constructivist instruction. The results showed that the positive correlation between teacher efficacy and constructivist instruction was stronger than the correlation between teacher efficacy and didactic instruction. The study suggests that policy makers and school leaders should try to improve teacher's efficacy beliefs so that innovative instruction could be effectively implemented by school teachers.