Using an extended theory of planned behaviour, this article is a report of a study to identify the factors that influence nurses' intention to integrate research evidence into their clinical decision-making. Health professionals are increasingly asked to adopt evidence-based practice. The integration of research evidence in nurses' clinical decision-making would have an important impact on the quality of care provided for patients. Despite evidence supporting this practice and the availability of high quality research in the field of nursing, the gap between research and practice is still present. A predictive correlational study. A total of 336 nurses working in a university hospital participated in this research. Data were collected in February and March 2008 by means of a questionnaire based on an extension of the theory of planned behaviour. Descriptive statistics of the model variables, Pearson correlations between all the variables and multiple linear regression analysis were performed. Nurses' intention to integrate research findings into clinical decision-making can be predicted by moral norm, normative beliefs, perceived behavioural control and past behaviour. The moral norm is the most important predictor. Overall, the final model explains 70% of the variance in nurses' intention. The present study supports the use of an extended psychosocial theory for identifying the determinants of nurses' intention to integrate research evidence into their clinical decision-making. Interventions that focus on increasing nurses' perceptions that using research is their responsibility for ensuring good patient care and providing a supportive environment could promote an evidence-based nursing practice. © 2012 Blackwell Publishing Ltd.