We identified 184,215 patients with hospitalization for a primary diagnosis of a migraine during our study period, of which 7,855 (4.3%) patients with a history of substance abuse were identified.  The migraine-substance abuse group consisted more of younger (Mean age 41.5 years vs 45.6 years) Female (72.4%) patients and were associated with higher 30-day readmission rates (13.1% vs 8%; p-value <.0001), a longer mean length of stay (3.2 days vs 2.6 days; p-value <.0001), higher discharge to another facility (2.2% vs 1.4%; p-value <.0001) and higher median cost of hospitalization ($7,011 vs $6,188, p-value <.0001). After adjusting for patient demographics and hospital characteristics, substance abuse was a significant predictor of increased 30-day readmission (OR: 1.52 95% CI:1.36-1.69, p-value <.0001). Incidence of comorbidities such as chronic lung disease (20.2% vs 15.4%), psychiatric disorders such as anxiety (31.1% vs 18.5%), mood disorders (43.2% vs 26.2%) and schizophrenia (2.5% vs 1.1%) were higher in substance abuse group.