This dataset contains anonymized individual-level data from a retrospective cohort study evaluating the effectiveness of CGRP monoclonal antibodies in the preventive treatment of episodic and chronic migraine. The data include demographic variables, diagnosis subtype, baseline and follow-up values for monthly migraine days (MMDs), MIDAS scores, and HIT-6 scores. All patients were treated at the Kiel Migraine and Headache Center between January 2020 and June 2023. The dataset supports the findings reported in the associated publication. Data were collected according to standardized institutional protocols and approved by the Ethics Committee of Kiel University (D404/23). Patients provided written informed consent for scientific use of clinical data. The dataset enables replication of responder rate calculations based on current guideline thresholds (≥50% MMD reduction for episodic migraine, ≥30% for chronic migraine, ≥30% MIDAS reduction, ≥5-point HIT-6 improvement) and supports further secondary analyses of treatment outcomes.