At present, surgical site infections (SSI) persist as key clinical problems, being one of the most important causes of intra-hospitalary morbidity and mortality, with a high prevalence. In addition, SSI constitute a heavy economic burden for health services, due to their high frequency, their tendency towards a chronic course and complications, and their high mortality. SSI also represent an important limiting factor for patients’ daily functioning and their capacity for autonomy and inde-pendence. This article discusses risk factors for SSI and ex-plores preventive measures for them. Recognition of the risk factors for SSI facilitates their identification in practice, and therefore their pertinent and opportune modification, as well as individualized stratification of each case in regards to risk level. These factors may be related to characteristics of the patients or the surgical procedure itself, and encompass tens of components between both categories. Abundant unknowns remain surrounding SSI in both clinical and epidemiological aspects, which may explain their persistence as frequent and relevant problems in contemporary practice. Concretely, fur-ther epidemiological characterization of SSI is required, as well as research on the true efficacy of the large catalogue of preventive measures that have been proposed historically. Moreover, it is also important to examine the cost-effectivity of these interventions, in light of the economic impact SSI exert worldwide.