Purpose: The purpose of this research is to determine the effect of jigsaw II technique on fourth grade students' real-life problem (non-routine problem) solving skills in science lessons in primary schools.Methodology: This research was carried out with 53 students attending the fourth grade of a primary school in Bandırma, Balıkesir both in experimental and control groups. Appropriate sampling method was preferred in the study. This research was designed according to quasi-experimental design, which is one of the quantitative research methods. The research data was collected by applying 5 real life problems (non-routine problems) within the experimental and control groups as pre-test and post-test. Mann Whitney U Test was used to analyze the obtained data.