Knowledge about what psychological characteristics underlie complicated grief (CG) is limited. The current study examined the five-factor personality traits in 81 bereaved adults with (n = 51) and without (n = 30) CG. A trained doctoral-level clinician evaluated participants using a structured, diagnostic psychiatric interview, and they completed self-report measures of grief and personality. A multiple regression model indicated that higher levels of neuroticism were associated with greater CG symptom severity, implicating neuroticism in the development of CG. Future prospective studies confirming it as a risk factor for the development of CG are warranted.