Despite the significant adverse consequences of deliberate firesetting, it has been unclear what proportion of individuals repeat this problematic behavior, owing to methodological differences and large variability in reported reoffending rates. A meta-analysis of 25 samples of untreated adults and children with a history of firesetting, examining reoffending over a follow-up period, was conducted. The base rates of reoffending from this meta-analysis indicated that between 57% and 66% of untreated firesetters engage in general reoffending, between 8% and 10% engage in criminal arson, and around 20% engage in deliberate firesetting behavior. The odds of firesetting during the follow-up period were 5 times greater for known firesetters in comparison with other offenders. Clinical and criminological correlates of reoffending, including age, are examined. Implications for enabling evidence-based practice with this population, including defensible risk assessments and treatment provision, are discussed.