Physicians have unique opportunities to help prevent firearm violence. Concern has developed that federal and state laws or regulations prohibit physicians from asking or counseling patients about firearms and disclosing patient information about firearms to others, even when threats to health and safety may be involved. This is not the case. In this article, the authors explain the statutes in question, emphasizing that physicians may ask about firearms (with rare exceptions), may counsel about firearms as they do about other health matters, and may disclose information to third parties when necessary. The authors then review circumstances under which questions about firearms might be most appropriate if they are not asked routinely. Such circumstances include instances when the patient provides information or exhibits behavior suggesting an acutely increased risk for violence, whether to himself or others, or when the patient possesses other individual-level risk factors for violence, such as alcohol abuse. The article summarizes the literature on current physician practices in asking and counseling about firearms, which are done far less commonly than recommended. Barriers to engaging in those practices, the effectiveness of clinical efforts to prevent firearm-related injuries, and what patients think about such efforts and physicians who engage in them are discussed. Proceeding from the limited available evidence, the authors make specific recommendations on how physicians might counsel their patients to reduce their risk for firearm-related death or serious injury. Finally, the authors review the circumstances under which disclosure of patient information about firearms to third parties is supported by regulations implementing the Health Insurance Portability and Accountability Act.