The effects of different trainings on the acquisition of mathematical problem-solving and self-regulation were studied with 249 eighth-graders. The study was conducted with 4 different trainings in German grammar schools. Each training consisted of six 90-min sessions on a weekly basis. The results confirm that it is possible to improve mathematical problem-solving and self-regulation competence through this kind of short training. The evaluation shows that the combination of self-regulatory and problem-solving strategies leads to the best effects for the improvement of self-regulatory competences. Furthermore, it is possible to improve problem-solving by practicing problem-solving and self-regulatory strategies or a combination of both.