There are many types of persons involved in the setting of fires. A 'firebug' sets a series of fires regardless of motivation. The professional torch sets fires to receive compensation. Pyromaniac is an indefinite term involving legal, psychological, and environmental aspects. Pyromania is defined as an overpowering desire to set fires. Persons who commit arson for profit are the most rapidly increasing group of firesetters. Profiles of arsonists who set fires for fraud appear to be based on an insignificant number of known offenders. Presumably, arson for profit is a rational act and is, therefore, not of great interest from a psychological standpoint. The professional torch is also motivated by money but is characterized by an antisocial personality with a pathological sense of confidence, impulsiveness, and lack of guilt or anxiety. The professional torch often works alone and is frequently a repeat offender. Several terms are used to describe the pathological firesetter, or pyromaniac. Pyromaniacs are motivated by psychological needs such as revenge, spite, power, and anger. They are often products of broken homes, are loners, and have histories of mental illness. Some studies have shown that pyromaniacs are compelled to set fires because of personality disorders, usually sexual deviancy. Pyromaniacs are not rational; they set fires even while being watched by investigators. A 9-entry bibliography and 23 footnotes are provided.