: The Impacts of Group Problem Solving on Students' Learning Motivation, Critical Thinking, and Learning Achievements. The aim of this study was to know the impacts of the implementation of group problem solving on the students' learning motivation, critical thinking, and learning achievements on concept and algorithm. This quasi-experimental research used pretest-posttest control group design. The research samples were the students of XI grade of Science 1 (problem solving class) and XI grade of Science 3 (expository class) at the Public Senior High School 6, Malang. The study was carried out in the 2013/2014 academic year. The results show that the students' learning motivation, critical thinking, and conceptual and algorithmic learning achievements in the problem solving class are higher than those in the expository class