The objective of this study was to investigate the effectiveness of muscle energy technique on postnatal low back pain. Thirty females suffer from postnatal low back pain, their age ranged from 25-35 years and their BMI ranged from 30-35 Kg/m² were participated in the study. They were divided randomly into two equal groups, group A included 15 women who had been treated with selected exercises program plus muscle energy technique, while group B included 15 women who had been treated with selected exercises program only. Assessment of all women in both groups were done before starting the study and after 8 treatment sessions ( 2 sessions per week for four weeks ) in form of pain pressure threshold, pain intensity, functional disability using Oswestry disability index and lumbar spine ROM. The results of this study showed a statistical significant improvement in both groups concerning pain pressure threshold, pain intensity, functional disability and lumbar spine ROM in favoring to (group A). Conclusion: These results indicate that muscle energy technique is valuable in management of postnatal low back pain.