During 2000-2002, the Task Force on Community Preventive Services (the Task Force), an independent nonfederal task force, conducted a systematic review of scientific evidence regarding the effectiveness of firearms laws in preventing violence, including violent crimes, suicide, and unintentional injury. The following laws were evaluated: bans on specified firearms or ammunition, restrictions on firearm acquisition, waiting periods for firearm acquisition, firearm registration and licensing of firearm owners, "shall issue" concealed weapon carry laws, child access prevention laws, zero tolerance laws for firearms in schools, and combinations of firearms laws. The Task Force found insufficient evidence to determine the effectiveness of any of the firearms laws or combinations of laws reviewed on violent outcomes. (Note that insufficient evidence to determine effectiveness should not be interpreted as evidence of ineffectiveness.) This report briefly describes how the reviews were conducted, summarizes the Task Force findings, and provides information regarding needs for future research.