AbstractBackground: Cervicogenic Headache (CGH) represents a major health problem, aggravating Quality of Life (QOL) and work productivity. The Suboccipital Muscles (SOM) have been identified as playing a role in cervical pain, and are therefore a target for rehabilitation.Aim of the Study: To asses the effect of CGH on myoe-lectrical activities of suboccipital muscles, functional activities and ROM of neck.Subjects and Methods: Thirty patients with CGH of both genders participated in this study. They were recruited from the out patient clinic of Kasr El-Ainy and thirty normal subjects, their ages ranged from 18-55 years old. They were randomly assigned into 2 experimental groups: Group A (18- 35 years)-group B (36-55 years) & 2 control groups: Group C (18-35 years)-group D (36-55 years). Myoelectrical activities was measured by Natus nicolet vikingquest to analyze the motor unit potentials by quantitative measures & neck range of motion was measured by Cervical Range of Motion (CROM) device and functional activities of the neck was measured by Neck Disability Index (NDI).Results: There was non significance increase in myoelec-trical activities of the suboccipital muscles in cervicogenic patients than normal subjects with (p-value=0.147). And there was statistical significant decrease in all ROM values and functional activities in cervicogenic patients than normal subjects in cervicogenic patients than normal subjects with (p-value <0.05).Conclusion: This study provides sound evidence for SOM alterations in in myoelectrical activities in patients with CGH.