This study aims to present the experiences of pre-service mathematics teachers' on skill-based problem solving-oriented lesson study. In the study, the activities related to the learning environments designed by the lesson study groups before and after the research lesson with a focus on problem solving are investigated. In this way, the study aims to reveal how lesson study affects pre-service mathematics teachers' awareness of teaching problem solving. In the study, 31 pre-service mathematics teachers first received a comprehensive training on teaching problem solving in mathematics for six weeks. Then, the pre-service teachers received a one-week training on the lesson study professional development model. In the last stage, they carried out problem-solving-focused lesson study processes under the guidance of the researcher with ten lesson study groups that they formed on the basis of volunteerism. Finally, the lesson study groups shared their experiences with the other pre-service teachers participating in the study by presenting the bulletins they prepared. The data were obtained through planning and evaluation meeting minutes, observation notes of research lesson practitioners and observers, initial and final lesson plans and documents. The data obtained in the study, in which the case study design of the qualitative research approach was preferred, were subjected to descriptive analysis using Polya's (1957) problem solving process steps framework. During the lesson study process that they experienced within the scope of the research, pre-service teachers shared their knowledge and experiences about the problem solving process and teaching with each other, as well as activities such as collaborative work in groups, designing and implementing teaching materials such as lesson plans and worksheets. According to the results obtained in the study, it was seen that the activities in the problem solving-oriented learning environments of the pre-service teachers varied thanks to the collaborative structure of the lesson study. In addition, it was seen that the pre-service teachers had the opportunity to experience the steps of the problem solving process and the instructions they could use in these steps on the students through the research lesson and then make the necessary rearrangements through evaluation meetings. Considering the opportunities offered by the collaborative and school-based structure of lesson study, it is thought that lesson study can be a functional model for pre-service teachers to use theory and practice together in courses on problem solving instruction.