OBJECTIVE: Interpersonal conflicts are among the most prevalent stressors before the onset of functional neurological disorder (FND), possibly reflecting maladaptive anger regulation. The authors examined whether FND patients have higher scores on anger-related measures compared with healthy control individuals and how anger regulation relates to personality factors. METHODS: FND patients (N=73, mean±SD age=44.2±16.7 years, 67% women) and healthy control individuals (N=43, mean age=43.3±17.0 years, 56% women) completed the State-Trait Anger Expression Inventory-2 (STAXI-2) to measure state and trait components of anger. Personality factors were assessed with the Personality Inventory for DSM-5-Brief Form and a structured interview to explore conflict and anger-related measures. RESULTS: Compared with control individuals, FND patients had significantly higher levels of state anger (U=1,031.5). After adjustment of analyses for trait anger, patients with FND still had higher levels of state anger than did control individuals (Wald χ CONCLUSIONS: FND patients reported higher levels of state anger than did healthy control individuals, even after analyses were adjusted for demographic and personality factors and trait anger. These findings emphasize the importance of anger regulation and personality factors in FND assessment and management.