Background: Clinicians commonly assess cervical range of motion (ROM), but it has rarely been critically evaluated for its ability to contribute to patient diagnosis or prognosis, or whether it is affected by mobilisation/manipulation. Objectives: This review summarises the methods used to measure cervical ROM in research involving patients with cervical spine disorders, reviews the evidence for using cervical ROM in patient diagnosis, prognosis, and evaluation of the effects of mobilisation/manipulation on cervical ROM. Data sources and study selection: A systematic search of MEDLINE, EMBASE, CINAHL, AMED and ICL databases was conducted, addressing one of four constructs related to cervical ROM: measurement, diagnosis, prognosis, and the effects of mobilisation/manipulation on cervical ROM. Study appraisal and synthesis: Two independent raters appraised methodological quality using the QUADAS-2 tool for diagnostic studies, the QUIPS tool for prognostic studies and the PEDro scale for interventional studies. Heterogeneity of studies prevented meta-analysis. Results: Thirty-six studies met the criteria and findings showed there is limited evidence for the diagnostic value of cervical ROM in cervicogenic headache, cervical radiculopathy and cervical spine injury. There is conflicting evidence for the prognostic value of cervical ROM, though restricted ROM appears associated with negative outcomes while greater ROM is associated with positive outcomes. There is conflicting evidence as to whether cervical ROM increases or decreases following mobilisation/manipulation. Conclusion and implications of key findings: Cervical ROM has value as one component of assessment, but clinicians should be cautious about making clinical judgments primarily on the basis of cervical ROM.