The effects of teachers' group incentives on student achievement are examined by reviewing theoretical arguments and empirical studies published between 1990 and 2011. Studies from developing countries reported positive effects of group incentives on student test scores. However, experimental studies from developed countries reported insignificant effects. Some of the evidence appears to show a positive association between small group size of teachers and the effectiveness of group incentives. Still, it is uncertain whether the key to successful group incentives in teaching emanates from the incentive size, teacher group size, teacher intrinsic motivation, or type of incentive (rank type vs. non-rank type). Furthermore, most studies show that individual teacher incentives have positive effects unlike studies on group incentives. However, there is a lack of comparative studies of group incentives and individual incentives. We conclude that current empirical evidence has unclear policy implications and recommend additional experimental research.