Education aims to educate individuals who can solve problems in daily life. Problem solving skills can be trained by getting students to settle as many problems as possible through the application of appropriate learning models in the classroom. This research was designed to integrate the guided inquiry learning model with a post organizer in order to improve students' physics problem solving skills. The purpose of this research was to determine the effect of guided inquiry learning model assisted by the post organizer on students' physics problem solving skills. This research used quasi-experimental with non-equivalent control group design. This research was conducted at SMAN 1 Gerung with a population of all students of class XI MIPA in the academic year 2019/2020. The sampling technique uses purposive sampling technique, namely class XI MIPA 4 as an experimental class and XI MIPA 7 as a control class. Indicators of problem solving assessed were useful description, specific application of physics, and mathematical procedures. Hypothesis testing used two-party t-test with the formula of t-test polled variance at a significance level of 5%. The conclusion of this research indicatd that there was an influence of the guided inquiry learning model assisted by the post organizer on the students' physics problem-solving skills.