Antibiotic-resistant bacteria have become an increasingly serious problem in Korea, and multidrug-resistant organisms (MDROs) such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococcus (VRE), and multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii have increased over the recent years. More seriously, the recent emergence of carbapenem resistance among Enterobacteriaceae is thought to be an urgent worldwide threat. Active surveillance have been identified as an important tool as an intensified infection control intervention for the control of MRSA and VRE and may be also an effective strategy for multidrug-resistant Gram-negative bacilli. Rapid detection using molecular methods could aid in the timely detection of MDRO carriers, and adequate application of infection control strategy could reduce the transmission of MDROs within hospital settings. (Ann Clin Microbiol 2015;18:103-110)