Background: Chronic migraine [CM] is a severe neurological disorder characterized by pulsating unilateral or bilateral headache episodes. In people with chronic migraine, onabotulinumtoxinA could reduce the frequency and severity of migraines. Patients report that the treatment is well tolerated.  
The Aim of The Work: The aim of this study was to evaluate the efficacy of onabotulinumtoxinA injection compared with the efficacy of onabotulinumtoxinA injection in combination with other oral prophylactics.
Materials and Methods: This observational study included one hundred five patients with chronic migraine attending the neurology clinic at Almoosa Specialized Hospital in Saudi Arabia, and was conducted from November 2019 to January 2021. Forty-five patients [42.9%] received an injection of onabotulinumtoxinA alone [group A], and 60 patients [57.1%] received a combined injection of onabotulinum- toxinA plus oral prophylaxis [group B].
Results: The study included 105 patients. The mean age of participants was 41.2 ± 5.7 years and ranged from 35 to 55 years. Seventy women [66.7%] and 35 men [33.3%] were affected. The mean frequency of migraine days showed a significant reduction from 17.6±10.3 days per month to 7.2±4.3 days after treatment in patients receiving onabotulinum toxin-A in combination with oral prophylactic medication, whereas it showed a less significant reduction from 16.4 ± 10.4 days per month to 9.1 ± 2.4 days in patients receiving onabotulinum toxin-A alone. Mean treatment frequency per month and mean duration of migraine attacks per hour were also significantly reduced after treatment in both groups. 
Conclusion: Onabotulinum toxin-A toxin injection is highly effective in treating patients with chronic daily migraine, reducing the number and severity of migraine attacks per month and improving the quality of life of migraine patients. However, it is even more effective when combined with other prophylactic medications depending on the patients' concomitant diseases.