Whether a researcher gains fieldwork access or not is influenced by multiple factors, including appropriate preparatory groundwork for the field. Objectives are to examine the entry process of nursing researchers into fieldwork to clarify the differences between the mechanisms established for obtaining fieldwork access to public and private health care institutions, and to analyse the characteristics of fieldwork access from the perspective of cultural ethnography using a structural dialectics model. Materials and Methodology. This was a qualitative study. Data-collection comprised a process of continuous observation at two health care institutions in Alicante. Results and Conclusions. In the context of nursing, gaining fieldwork access is strongly influenced by the perceived tradition of research in nursing and the hegemony of other disciplines. Once access has been obtained, however, the observer’s approach must depend on the primary objective of the research.