Recent human cases of infection with a novel influenza A(H1N1) virus have been identified both internationally and in the United States. Since there has been human to human transmission and the new virus has the potential to become pandemic, it is timely to examine the legal issues surrounding this emerging public health threat. This report provides a brief overview of selected legal issues including emergency measures, civil rights, liability issues, and employment issues. There are a number of emergency measures which may help to contain or ameliorate an infectious disease outbreak. The Public Health Service Act and the Stafford Act contain authorities that allow the Secretary of Health and Human Services and the President, respectively, to take certain actions during emergencies or disasters. While the primary authority for quarantine and isolation in the United States resides at the state level, the federal government has jurisdiction over interstate and border quarantine. Border entry and border closing issues may arise in the context of measures designed to keep individuals who have, or may have, influenza A(H1N1) from crossing U.S. borders. Aliens with the H1N1 virus can be denied entry, but American citizens cannot be excluded from the United States solely because of a communicable disease, although they may be quarantined or isolated at the border for health reasons. Airlines have considerable discretion to implement travel restrictions relating to the safety and/or security of flights and other passengers and crew. In addition, the federal government has broad legal authority to regulate and control the navigable airspace of the United States in dealing with incidents involving communicable diseases. States have authority to initiate other emergency measures such as mandatory vaccination orders and certain nonpharmaceutical interventions such as school closures, which may lessen the spread of an infectious disease. The International Health Regulations adopted by the World Health Organization in 2005 provide a framework for international cooperation against infectious disease threats. The use of these emergency measures to contain the influenza A(H1N1) virus outbreak may raise a classic civil rights issue: to what extent can an individuals liberty be curtailed to advance the common good? The U.S. Constitution and federal civil rights laws provide for individual due process and equal protection rights as well as a right to privacy, but these rights are balanced against the needs of the community. Liability issues may become particularly important during the influenza A(H1N1) virus outbreak. The Public Readiness and Emergency Preparedness Act limits liability with respect to the use of countermeasures for pandemic flu or other public health threats. A patchwork of federal and state laws exists which generally operates to protect volunteers, which may include volunteer health professionals (VHPs) under certain circumstances, and there are also laws that trigger liability protection specifically for VHPs. Questions relating to employment are among the most significant issues presented by an influenza pandemic, since, if individuals fear losing their employment or their wages, compliance with public health measures such as social distancing and isolation or quarantine may suffer. It would seem possible for a court to conclude that the isolation or quarantine of individuals during a pandemic serves the public good and that the termination of individuals who are isolated or quarantined violates public policy. Employees may also have some job protection under the Family and Medical Leave Act.