This issue of Clinics in Laboratory Medicine, Guest Edited by William Pasculle, MD, and James Snyder, PhD, on the topic of Emerging Pathogens will include the following article topics: Avian Influenza; Listeriosis; Shiga Toxin-producing E Coli; West Nile Virus; Hanta Virus; Malaria; Metapneumovirus; Dengue; Ebola; Staph aureus MRSA; Chikunguna; Bocavirus; HIV; Tickborne Bunyaviridae; Tickborne Flaviviridae; TB; SARS; Yellow Fever; Anaplasma/Ehrlichica; Prion Diseases; Lyme Disease; and Clostridium difficile.