Objective: In three kvasi-experimental single-case studies regarding patients with neck-pain who after sub-grouping using Treatment Based Classification (TBC), were placed in the subgroups centralization or mobilization, describe how and why they were placed in that particular subgroup and then to evaluate the effects on function and pain of the specific treatment proposed for that subgroup.    Method: The process of sub-grouping is described. Function and pain were measured with the Neck Disability Index (NDI) and Numeric Pain Rating Scale 0-10 (NPRS) before, during and after the treatment-period and 1 month after the treatment-period had ended.    Results: The use of TBC showed positive results with increased levels of function and decreased patient-reported neck pain in all three single-cases.    Conclusion: The TBC-system may be used for improving function and pain in patients with neck pain. More studies of the validity and reliability and randomized studies of the TBC-system are needed before it could be recommended generally for physiotherapists.