Purpose The Core Outcome Measures Index (COMI) is a short and multidimensional scale covering all domains recommended to be included in outcome measures for patients with neck pain. The purpose of the present study was to translate and cross culturally adapt the COMI into Turkish and to test its reliability and validity in patients with neck pain. Methods One hundred and six patients with a complaint of chronic neck pain (> 3 months) were enrolled in the present study. Participants completed a questionnaire booklet containing the COMI-neck, Neck Disability Index (NDI), Neck Pain and Disability Scale (NPDS), Short Form-36 (SF-36), and pain Numeric Rating Scale (NRS). The validation of the COMI included the assessment of its construct validity and reliability. Results Cronbach's alpha value of the questionnaire was found to be 0.774 indicating a high internal consistency. Intraclass correlation coefficient values for test-retest reliability were found to be in the range of 0.817-0.986, which indicates a sufficient level of test-retest reliability. Pearson's correlation coefficient values of the COMI with SF-36, NDI, NPDS, and NRS ranged between 0.417 and 0.700, indicating a good correlation. Conclusion Considering the analyses, it was concluded that the Turkish version of the COMI is a valid and reliable scale for chronic neck pain patients.