Arson rings may be defined as two or more persons banding together to commit the crime of arson. Of all the crimes committed in the United States, those committed by arson rings may be the most serious, far reaching, and underreported. Major motives for the activities of arson rings are direct or indirect profit. Direct profit generally involves some method of gaining proceeds of insurance policies on property. The primary indirect motive involves elimination of competition. Often, arson rings require the complicity of business persons, insurance brokers, adjusters and realtors, as well as the criminals who actually set the fire. Efforts by law enforcement officials to link primary suspects to the act are often futile. Methods of operation vary; they may include the use of large amounts of gasoline or the use of incendiary devices. Arson committed to obtain insurance proceeds is considered difficult to prove. Traditional crime fighting methods are somewhat effective against indirect profit motives, but direct profit arson for insurance will require new approaches. The most effective of these approaches have been designed by insurance companies. For example, in an attempt to identify repeaters in insurance scams, insurance companies have established the property loss register, a computer listing which identifies owners, lawyers, tenants, and others who have repeated involvement in fire claims. Nine footnotes and four bibliographical references are provided.