The aim of the study is to increase primary school teachers' attitudes regarding professional development through the university-school cooperation method, support their professional development, and create a university-school cooperation model. The study was carried out via embedded experimental design among mixed research methods. In total, 49 primary school teachers in the study working at the primary schools in three different settlement areas, i.e., village, district and city, that have a disadvantageous position in Eskisehir province. As for the locations and socio-economic status of the schools where the attendant primary school teachers work, it can be stated that these schools are disadvantageous with regard to participation in professional development activities. Within the study, a professional development attitude scale and an in-service attitude scale were applied to the teachers at the beginning and end of the training process in the data collection stage. Then, the teachers' opinions about the professional development trainings were obtained and the training diaries, which were kept in this process by the teachers, were used. At the end of the study, it was found out the fact that there was a positive difference in the attitudes of the primary school teachers regarding the Professional development and in-service training thanks to the professional development activities performed. It was further found out the fact that the teachers considered the performed activities useful, productive and efficient and a model was revealed for professional development carried out within the scope of university-school cooperation. [This article includes an extended summary in Turkish.]