Background The success of various therapy methods in the treatment of insomnia and poor quality sleep, both of which play an active role in the chronicization process of migraine, has been the subject of investigation. The aim of this research was to evaluate the success, acceptability, and efficacy of greater occipital nerve block (GON-B) therapy in chronic migraine (CM) patients in improving their sleep quality and developing their beliefs about sleep . Methods The study included 40 patients with CM from the general population who agreed to receive blockade therapy. Before the injection treatment, 1-week sleep diaries as well as depression and anxiety symptoms were examined. The Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Pre-Sleep Arousal Scale (PSAS), Epworth Sleepiness Scale (ESS), and Dysfunctional Beliefs and Attitudes about Sleep (DBAS) scales were measured and evaluated both before and after the completion of 3 months of treatment. Results Thirty-seven patients with CM successfully completed our 12-week treatment period. The anxiety and depression scales of the patients decreased after 3 months (p < 0.001). PSQI and its subgroups ratings significantly improved after treatment (p < 0.001). Similarly, ISI, ESS, PSAS, and DBAS test scores also improved after treatment (p < 0.001). Conclusions This study provides evidence as to the applicability and acceptability of GON-B in CM treatment in terms of increased sleep quality; improved sleep beliefs, attitudes, and behaviors; and arousals and decreased insomnia findings.