The pull-out resistance of polyester strip reinforcement in crushed stone aggregate was studied with a large-scale pull-out box developed at the Faculty of Civil Engineering in Osijek. Several laboratory pull-out tests of polyester strips in crushed stone aggregate with different grain size distribution and coefficient of uniformity were carried out. The material was classified as poorly-graded and well-graded crushed stone aggregate. The soil/reinforcement interaction parameters deduced from these tests show that grain size distribution of material has a very big influence on the friction coefficient. The results of these tests were compared with similar tests reported by Lo (1998) and Abdelouhab et al. (2009) but for different types of soil. The test results show that the friction coefficient of well-graded crushed stone aggregate and polyester strip is significantly higher than soil-strip interaction parameters deduced from pull-out tests with sand and/or gravel soil type.