Abstract Background: Several studies have indicated the clinical and functional importance of lumbar lordosis. It is a key component in maintaining the sagittal balance. Aim of Study: To investigate the effect of lumbar hyper-lordosis correction on crainovertebral angle in chronic low back pain patients. Subjects and Methods: 30 patients of both genders diag-nosed as chronic low back pain with lumbar hyperlordosis (cobb anlge >40 degrees) selected from outpatient clinic of the faculty of physical therapy, Beni Suef University through the period between October 2019 to January 2020. Their ages ranged from 20 to 35 years. Patients were assigned randomly by sealed envelope into two groups after signing institutionally approved consent. Group A (Experimental group): 15 patients received muscle energy technique (MET) for 3 sessions/week for 4 weeks. Group B (Control group): 15 patients received William program for 3 sessions/week for 4 week. Lumbar lordosis angle was measured by plain X-ray imaging, cranio-vertebral angle by photographic analysis method, pain intensity level by visual analogue scale, trunk range of motion by tape (flexion, extension, side bending and rotation) before and after four weeks of treatment. Results: The study findings revealed that there was a significant improvement in the craniovertebral angle of both groups post treatment compared with that pre treatment (p= 0.0001), There was significant increase in trunk range of motion in both groups post treatment compared with that pre treatment (p=0.0001), There was a significant decrease in pain intensity on VAS in the both groups post treatment compared with that pre treatment (p=0.0001). Conclusion: The correction of lumbar hyperlordosis had a positive effect on improving craniovertebral angle, improving trunk range of motion, and decrease pain level in chronic low back pain patients.