Surveillance is usually defined as the ongoing and systematic collection, analysis and interpretation of health data essential to the planning, implementation and evaluation of public health practice. During recent years, most of these programmes have been developed in the field of antimicrobial resistance and nosocomial infections, but efforts have also been made in other areas. Recent experiences of emerging microbial threats, including severe acute respiratory syndrome and new influenza variants affecting humans, the re-emergence of infectious disease problems and the possibility of bioterrorism have evidenced the need for implementation of infectious disease surveillance programmes. clinical microbiology laboratories play a pivotal role in these programmes. They have the first opportunity to detect these problems and should participate in the design of reporting strategies and dissemination of this information. Policies for the flow of data to national and international authorities should be established using passive surveillance strategies. However, active surveillance programmes taking advantage of new methodologies, including virtual tools and mathematical programs, should be the goal for early detection of unusual patterns of microbial pathogens, outbreaks and healthcare-associated infections. In addition, early implementation of response strategies should be designed and performed with the cooperation of microbiology laboratories, and intervention and response protocols should be defined with the participation of clinical microbiologists.