OBJECTIVE To test the long-term clinical effectiveness (follow-up at 3, 6 and 12 months) of an outpatient combined group and individual cognitive-behavioral treatment (CBT) for headache patients following standard medical care. A decrease in headache intensity, frequency, headache-specific impairment, depression, and change of pain-related cognitions was expected. BACKGROUND The efficacy of CBT for primary headaches has been confirmed in research, yet the translation into clinical practice has remained untested thus far. DESIGN In this single-group outcome study, 87 headache patients diagnosed with migraine and/or tension-type headache received (1) headache-specific medication for 10 weeks and (2) a subsequent CBT treatment made up of 13 individual and 12 group sessions consisting of psychoeducation, progressive muscle relaxation, coping strategies for pain and stress, and goal setting skills. Booster group sessions after 3 and 6 months were implemented to stimulate individual goal attainment, and follow-up measures were recorded up to 12 months. RESULTS A significant decrease was found for all primary and secondary outcome criteria, ie, average headache intensity (prae M: 6.0, standard deviation [SD]: 1.5 vs follow-up [FU] 1 year M: 5.1, SD: 1.9), headache frequency (prae M: 16.0, SD: 9.5 vs FU 1 year M: 13.4, SD: 9.9), and catastrophizing (prae M: 3.4, SD: 1.0 vs FU 1 year M: 2.6, SD: 1.1). Coping strategies were increased (prae M: 3.4, SD: .9 vs FU 1 year M: 4.0, SD: 1.0). CONCLUSION CBT treatment is a useful component within a routine clinical setting and can improve standard medical care thereby helping patients in managing their headache pain.