Burnout syndrome is a phenomenon that is becoming ever more widespread, especially in workers who have heavy workloads and time pressures, such as nurses. Its progression has been shown to be related to both individual and work-related variables. The objective of this study was to examine the risk and protective roles played by work-related and personal variables, both sociodemographic and psychological, in the development of burnout in nurses. The sample was made up of 1236 nurses. Exploratory tests were performed to understand the relationships between burnout and the other variables, as well as a binary logistic regression to understand their roles in the incidence of this syndrome. Lastly, a regression tree was constructed. The results showed that the sociodemographic variables examined in the study were not related with levels of burnout in nurses. However, certain work-related variables were, such as spending more time with colleagues and patients, and reporting good quality relationships with colleagues, superiors, patients and their families, exhibiting a significant, negative relationship to the presence of burnout. Of the psychological variables, the stress factors conflict-social acceptance, and irritability-tension-fatigue, along with informative communication were found to be risk factors for the appearance of burnout in nurses, in contrast to the communication skills factor, empathy, and energy-joy, which exercised a protective function. The irritability-tension-fatigue factor was the best predictor for the appearance of burnout in nurses.