The objective of this study is to determine the learning outcomes in the IPAS subject for Grade IV students at SDK Sawu through the implementation of the Problem Based Learning model. This research is a Classroom Action Research (CAR) using the Kemmis and Mc. Taggart design, which consists of four stages: planning, action, observation, and reflection. After the observation stage, reflection is carried out to evaluate the strengths and weaknesses of the learning process and to plan improvements for the next cycle. This reflection serves as the basis for refining the actions in the following cycle. The subjects of this study are 16 fourth-grade students at SDK Sawu, consisting of 10 female students and 6 male students. Data collection techniques include observation, learning outcome tests, and documentation. The instruments used are observation sheets for teacher and student activities as well as evaluation test items. Data were analyzed using descriptive quantitative analysis by calculating the average scores and the percentage of class mastery. Based on the data analysis in Cycle I, the average learning result was 67.5%, with a classical completeness percentage of 37.5%, which falls under the "low" (not yet complete) category. In Cycle II, the average learning result increased to 83.5%, with a classical completeness percentage of 87.5%, which is categorized as "good" (complete). Based on these results, the study is considered successful because 80% of the students achieved learning mastery at a good level. It can therefore be concluded that the implementation of the Problem Based Learning model in the IPAS subject can improve student learning outcomes in Grade IV at SDK Sawu.