There is a growing interest in promoting nursing research in Spain, especially with the European Convergence of educational programmes and qualifications. The aim of this study was to contribute to the development of nursing research among clinical nurses in a Spanish hospital. To do so, it explored the nursing research culture in a hospital and, designed and implemented an intervention to increase nursing research by developing research capability and modifying inhibiting factors in the context. This project followed a realistic evaluation approach. It was divided into three phases: baseline, development and evaluation. The baseline phase, conducted with clinical nurses and ward managers in a University Hospital, aimed at gaining an understanding of the nursing research culture in a hospital. This information was used for the development phase, which comprised the design and implementation of an intervention. The intervention, implemented over one year, consisted of the establishment of a mentors' network in the hospital, and an educational program with seminars, research methods courses and journal clubs. The evaluation phase was conducted to study the intervention outcomes looking at the contexts and the intervention mechanisms, through ward managers', clinical nurses' and mentors' views. Several methods of data collection, quantitative and qualitative, were used along the different phases of the study: self completion questionnaires, objective tests, scales and focus groups. The results indicated that the nursing research culture of the hospital developed moderately after the intervention as shown by an increase in participants' research capability (knowledge, skills and attitudes) and a decrease in some of the inhibiting factors identified in the baseline phase. The knowledge provided by this study helped to understand how a carefully designed intervention, based on an understanding of the context, could contribute to nursing research development. This intervention, and the understanding of why and how it worked, could be used as a model in other hospitals.