Previous studies have shown that the profession of nursing has inherent risk factors that may contribute to Substance Use Disorder among nurses. One of those risk factors may be codependency. This study explored the relationship between codependency and self-reported history of treatment for SUD among nurses. It also compared nurses' codependency scores by gender, race, birth order, having experienced or witnessed physical violence in the family of origin, having a parent or primary caregiver with SUD, and having a parent or primary caregiver with a history of mental illness. One thousand nurses with active licensure in a southeastern state were mailed survey packets which included the Spann-Fischer Codependency Scale and a demographic questionnaire. Two hundred and two surveys were returned. The results indicated that the nurses' codependency scores differed significantly when compared by history of treatment for SUD. Nurses who reported treatment for SUD had higher codependency scores than nurses who reported no treatment for SUD. The nurses also differed significantly in their codependency scores when compared by their having witnessed or experienced physical violence in their family of origin. Those who reported a history of witnessing or experiencing physical violence in their family of origin had higher codependency scores than those who did not. The third significant finding was that nurses who reported having a parent or primary caregiver with a history of mental illness had higher codependency scores than those who did not.