Purpose: The aim of this investigate the effectiveness of the conventional physical therapy and Mulligan mobilization technique in the treatment of Cervicogenic Headache (CH) and to compare the effectiveness of these two methods. Methods: A total of 40 patients with CH were randomized into conventional physical therapy group (Group 1, n=20) and Mulligan mobilization group (Group 2, n=20). Neck lordosis, range of motion (ROM), Cervical Performance Tests, Visual Analogue Scale (VAS), Neck Disability Index, Beck Depression Scale measurements were recorded at baseline and at two weeks after the treatment. Results: VAS, Neck Disability Index and Beck Depression Scale decreased and ROM, cervical performance and lordosis angle increased significantly in both groups (p=0.010). Conclusions: Both treatments were found to have positive effects on radiological and clinical findings of CH, but Mulligan mobilization technique was found to be more effective in all evaluations except neck extension and right lateral flexion ROM measurements