BACKGROUND Although the clinical importance of Acinetobacter pittii and Acinetobacter nosocomialis has increased in the nosocomial setting in the last decade, infections caused by Acinetobacter baumannii still have the highest clinical relevance. The most important features of this latter species are the ability to persist in the hospital environment and the multi-drug, extended-drug or pandrug resistance they may present which compromises the treatment of infections caused by this microorganism. METHODS In the present review, the authors describe the molecular bases of the acquisition of resistant mechanisms as well as different current and potential future strategies to treat infections caused by multi-drug resistant A. baumannii. CONCLUSIONS With the increase in resistance to carbapenems, colistin has been extensively used, however some data suggest that the doses recommended are insufficient before a steady state is reached, suggesting that the administration of a loading dose on initiation of treatment may be beneficial. Combinations of antibacterial agents such as impenem plus sulbactam or imipenem plus colistin have been successfully used to treat VAP. Nonetheless, future alternatives for treating A. baumannii infections should be explored.