BackgroundSpecific neck exercise is effective in the management of cervicogenic headache (CH). The Spinertial device was designed to facilitate craniocervical flexion and extension training, but its efficacy, judged on change in headache impact, has not been tested. ObjectiveTo compare guided and progressive resisted specific neck exercise targeted to the craniocervical flexors and extensors (SNE-fe) performed with Spinertial device to progressive SNE-fe without the device in a cohort with CH. DesignRandomised controlled trial. MethodsTwenty-eight participants with CH were randomly allocated to the Spinertial group (SG) or SNE-fe exercise group without the device (EG). Both groups performed 12 sessions of SNE-fe over six-weeks. The primary outcome was headache impact (HIT-6). Secondary outcomes were the craniocervical flexion test (CCFT), upper cervical (UCS) and lower cervical range of movement, flexion rotation test (FRT) analysed as more or less restricted side (MRS, LRS), the self-reported global rating of change (GROC-scale) and satisfaction with the exercise program (PACES). Outcomes were measured at baseline, post-intervention (T1) and after 1-month (T2). ResultsSignificant between-groups differences were found favouring the SG for HIT-6 (T1 p = 0.010, d = 0.5; T2 p < 0.004, d = 0.4), CCFT, UCS ROM, FRT MRS, FRT LRS, PACES and GROC-scale (T1: all p < 0.01; T2: all p < 0.01). Effects sizes were large (>0.8) at T1 and T2. No between-groups differences were found for lower cervical ROM. ConclusionTraining with the Spinertial was more effective than SNE without the device for improving the impact of headache, the endurance of deep neck flexors and UCS ROM in participants with CH.