Carbapenems are active beta-lactam antibiotics versus most of the gram positive and gram negative microorganisms and anaerobes although their activity is lacking in the case of Staphylococcus sp. resistant to methicillin, Enterococcus faecium and Streptococcus pneumoniae with high resistance to penicillin and some gram negative bacilli which naturally produce an methaloenzyme able to hydrolyze them such as Stenotrophomonas maltophilia. Imipenem, the first synthetized carbapenem requires administration with cilastatin to avoid inactivation by renal dehydropeptidase 1. Meropenem does not require being taken with the renal enzyme inhibitor, with its activity being similar to that of imipenem. In abdominal infection the carbapenems have shown to be the authentic monotherapy in this type of infections being as effective as the different schedules of antibiotic associations normally used. Treatment with carbapenems in bacterial meningitis should be currently limited to the cases produced by gram negative bacilli producers of wide spectrum beta-lactamases (WSBL), cases of meningitis by Pseudomonas aeruginosa or gram negative bacilli producers of inducible cephalosporinase. Meropenem is the carbapenem of choice probably in these cases because the carbapenems are often the only active antibiotics and meropenem, specifically, does not have the risk of convulsions observed with imipenem-cilastatin. The carbapenems have shown to be useful in skin and soft tissue infections as well as in obstetric and gynecologic infections as monotherapy similar to the schedules of the currently used antibiotic associations. In the case of nosocomial pneumonias, all the studies have evaluated the carbapenems in monotherapy as useful and effective, specially in the case of pneumonia by gram negative bacilli. Finally, in non filiated nosocomial sepsis and specially in the case of neutropenic patients, the use of carbapenems is particularly attractive in gram negative sepsis in intensive care units. The appearance in the last few years of strains of gram negative bacilli, producers of wide spectrum beta-lactamase or stable repressed hyperproducers of class I chromosomic cephalosporinase, as well as other multiresistant gram negative bacilli, such as Acinetobacter baumanii make the carbapenems, in many cases, the only effective antibiotic in this type of infections.