After the effectiveness of self-regulation training outside school was demonstrated, a self-regulation intervention was developed to foster the learning achievement in regular math classes. Based on the theoretical framework of self-regulated learning, self-regulation training was integrated into a math class unit. The evaluation of the intervention concerning 53 sixth-grade students took place in a pretest/posttest-control-group design. One teacher taught one class (control group) merely mathematical topics and another class (experimental group) in the same subject combined with self-regulative strategies. The results revealed that it is possible to support self-regulation competencies and mathematical achievement by self-regulation intervention within regular mathematics lessons of 6th-grade students. (Contains 3 figures and 2 tables.)