Overcrowding in emergency departments (ED) jeopardizes quality and access to health care, which represents a major issue for service delivery. This study determined predictors of frequent ED utilization among 320 patients recruited from six hospital ED in Quebec (Canada). Data collection included patient interviews and administrative databanks. A hierarchical linear regression analysis was performed using the Andersen Behavioral Model as a framework, with variables organized into predisposing, enabling, and needs factors. Results showed that needs factors were most strongly associated with ED utilization, particularly schizophrenia and personality disorders. Predisposing and enabling factors each contributed one variable to the model: past hospitalization for Mental Health (MH) reasons, and having regular care from an outpatient psychiatrist over the 12 months prior to interview at the ED, respectively. Increasing integration of MH services in networks may reduce unnecessary ED utilization and overcrowding, while providing better accessibility and care continuity for patients who visit ED for MH reasons.