This article discusses personal and organizational liability for the negligent provision of information by health science librarians providing information regarding patient diagnosis and treatment. It notes claims in the library literature that liability exists for providing faulty information, but these claims do not state or explain the legal basis for such liability. It identifies three basic information retrieval and communication services provided by reference librarians and characterizes the negligent provision of information as a failure to exercise care in one or more of the three. With regard to personal liability, it identifies the relevant law, the tort of negligent misrepresentation involving risk of physical harm, and outlines the elements that a plaintiff would have to establish to sue successfully. With regard to organizational liability, it notes that a plaintiff would use one of two common law theories: either the vicarious liability doctrine of respondeat superior or the direct liability negligent hire theory of recovery.