Among antibiotic-resistant organisms, the Gram-negative bacteria are now the most important challenge because of the rapid worldwide spread of mechanisms conferring resistance to multiple drugs. The most recent and worrying problem is the emergence and spread of carbapenemases. Additionally, carbapenem-resistance is known to be very frequent among Acinetobacter baumannii isolates for many years. Overall, the therapeutic options available against carbapenem-resistant Enterobacteriaceae (CRE) and A. baumannii (CRAB) are very limited. The best available treatment (BAT) against CRE is unknown, which is a challenge for therapeutic decisions and also for the design of randomized trials with new drugs. The generic objectives of EURECA are to obtain high‐quality observational data to inform the design of randomized controlled trials for complicated intraabdominal infections, pneumonia, complicated urinary tract infections and bloodstream infections due to Carbapenem-resistant Enterobacteriaceae (CRE) and carbapenem-resistant Acinetobater baumannii, and to provide cohort data that could eventually be used as historical controls for future comparisons with new drugs targeting CRE. This will be achieved by a prospective, multinational cohort study of patients with targeted infections due to CRE and CRAB, and by matched case-control-control studies.