Learning Objects (LOS) within their new features, give new opportunities to learners and educators. LO based learning environments are mostly used within web environments, especially through distance education. This study presents an application about the use of LOs in a real classroom environment. In this application, a Learning Object Repository (LOR) relevant to secondary school mathematics curricula has been prepared and published on the web. The research sample consists of thirty students from a high school at 9th grade. In order to answer the research questions about the implementation of LOs for mathematics teaching in a high school classroom, qualitative and quantitative data were obtained both from the teacher and students participated in the study. The analysis of the data illustrated that students were easily able to follow the instructions of LOs and practise activities within LOs. The attitudes and approaches of students were generally positive. In despite of inconveniency with the teacher's familiar instructional practices, she also expressed her positive opinions about the learning and motivational effects of LOs. These findings support the idea that the use of LOs can be an effective learning tool in high school mathematics classrooms. (C) 2010 Elsevier Ltd. All rights reserved.