The Nosocomial Infection Surveillance Program in Catalonia (VINCat) monitors surgical site infection (SSI) in elective colorectal surgery since 2007 in 55 public and private acute care hospitals. These hospitals perform active and prospective standardized surveillance of elective colorectal resections. Post-discharge surveillance is mandatory at least up to 30 days after surgery. Hospitals are classified according to their size into three groups: \>500 hospital beds; 200-500 beds; \<200 beds. Aim. To examine the effect on SSI rate of a specific preventative bundle in elective colorectal surgery. Methods. Pragmatic study using VINCat prospective colorectal database from 2007 to 2018. In 2016, a bundle of six preventative measures was recommended to the VINCat hospitals. To compare the results of SSI before (baseline phase, BP) and after the bundle implementation (implementation phase, IP) a logistic regression model has been established. The results will be shown as Odds Ratio (OR) and the corresponding confidence intervalsCI95. The significance level will be fixed at 5% (P \< 0.05).