Anastelosis, a conservation and presentation technique in archaeological sites, is the practice of reassembling the scattered original parts of the structures. It can be stated that anastelosis ensures a better protection of the architectural fragments by re-placing them in their original places and contributes to the necessity of conservation practice by providing three-dimensional information about the structures. The aim of this study was, to contribute to the conservation and presentation of the structures in archaeological sites and to determine the basic principles to be considered during the implementations by analysing and evaluating the anastelosis implementations in Western Anatolia. Accordingly, anastelosis examples of Ancient Greek and Roman period temple structures that had significance in polis and sanctuaries were selected from Western Anatolia. Method of the study was on-site examination of the implementations, archive and literature research and evaluation of the information obtained from excavation reports prepared by the excavation team. In the evaluation, anastelosis principles, within the framework of international conservation documents and publications, were determined as emphasis of the structure within site scale and in original state, structural and visual integrity of the monument, authenticity, reliability, distinguishability, visual and material compatibility, reversibility and re-treatability. It can be stated that the implementations examined, in line with these principles, emphasized the importance of the temples in ancient times, contributed to better conservation of the scattered structure elements and transfer of information concerning the constructions. However, in some cases, the implementation has transformed to restoration or reconstruction as the authenticity principle could not be met; the temple became dominant than its original due to the inability to emphasize the structure within site principle; the mass of the temple could not be perceived due to lack of integrity principle; and the implementations that need to be redone have been identified as the use of new materials damaged the original elements.