In this study, we examined the risk-related characteristics of mentally disordered patients who had either been (1) involved in a firesetting incident or (2) involved in a nonfiresetting comparison incident while under the care of the National Health Service (NHS). A total of 132 participants were recruited from an NHS Care Group in England (66 mentally disordered firesetters, 66 mentally disordered comparisons). Logistic regression was used to model the ability of static, dynamic, and incident-related factors in predicting whether a patient had set a fire (including gender-sensitive subanalyses), whether a patient firesetter was male or female, and a one-time or repeat firesetter. We identified a cluster of variables that predicted firesetting status. We also identified key factors that predicted female patient firesetters relative to female patient controls who engaged in other undesirable behaviors and male patient firesetters. A cluster of variables predictive of repeat versus one-time firesetting also emerged. Findings are discussed in relation to further development of risk-related firesetting theory.