To evaluate a contextually framed intervention to increase nursing research capacity among clinical nurses in a Spanish hospital. In Spain, there has been a paucity of nursing research and a lack of nursing research culture. Currently, with the European Convergence of educational programmes and qualifications, there is a growing interest in promoting nursing research in this country. A quasi-experimental design. Using a control (n = 81) and an intervention group (n = 89) of nurses, pre- and postintervention data were collected from both groups to evaluate the impact of the intervention at three times. The intervention, implemented over one year, consisted of the establishment of a mentors' network and an educational programme with research courses and journal clubs. Data collection methods included questionnaires, objective tests and scales. The nursing research capacity of the hospital developed moderately after the intervention, with an increase in participants' research capability (knowledge, skills and attitudes) and a decrease in some of the inhibiting factors identified in the context. A new comprehensive and contextually framed intervention to develop nursing research capacity has been designed, implemented and evaluated in a hospital. It contributed to the development of the nursing research culture in the context. Relevance to clinical practice. An increase in nursing research activity could improve the quality of nursing care through the incorporation of research evidence in practice. This intervention could be used as a model in other hospitals, and it should be evaluated in other contexts. © 2011 Blackwell Publishing Ltd.