The purpose of this research was to analyse the level of student learning activities and to increase their competence in mathematical problem solving through Problem Based Learning method and scientific approach. This research was designed based on a classroom action. The subjects were Grade 8 students of Muhammadiyah Junior High School in Batu Malang. The research was conducted in 2015. Data were collected by observing students' learning activity, while tests were conducted to measure the students' ability in mathematical problem solving. Descriptive analysis was conducted to analyse the student learning activities and the level of their mathematical problem-solving ability. The results of this study showed that the implementation of mathematical learning using Problem Based Learning method and scientific approach can enhance students' learning activities and mathematical problem-solving ability.