Back pain is one of the common symptoms during pregnancy. In some women, it’s starts early pregnancy and remains throughout the end of pregnancy. In other women it worsens and continuous to hinder even after the baby born. As the uterus expands, it weakens the abdominal muscles and alters center of gravity. They also affect the posture and lead to pressure on back, presses a nerve, the back begins to ache. During pregnancy, the ligament in the body naturally become softer and stretch to prepare for labor. This can put a strain on the joints of the lower back and pelvis, which can cause backache. Recent studies reported an average duration of 6.5 weeks of sick leave as a result of moderate lumbar pain, approximately 70% of women will report low backache at some points. The incidence of low back pain is 50-80% during antenatal period. During antenatal period, the occurrence of low back disorder could have global consequence involving physical, psychological and social impacts among women and their unborn children. The main aim of our study was to assess the effectiveness of backstretch exercise on low backache among antenatal mothers admitted in tertiary care hospital at Puducherry.Methodology:A quantitative research approach and true experimental research (two groups’ pre and posttest) design. Sixty samples with low backache were selected by simple random sampling technique (Lottery Method). Thirty in group I(Experimental) received back stretch exercise and 30 in group II (control) has received routine care. In pre-test demographic variables was collected by using structured interview schedule and the level of low backache assessed byEric.L.Linlow backache scale during motion, standing and sitting.Backstretch exercise given to the experimental group. It is technique to reduce the level of low backache, gentle spine movements.Gentle Spine Movementsfor 5 minutes and Cat – cow method for 5 minutes.Repeat each step for 3 times. Backstretch exercise was continued for 3 days morning and evening. In post-test level of lowbackache was assessed with same Eric.L.Linlow backache scale by the 4th day. The data were analyzed by using descriptive and inferential statistics like frequency, percentage, mean, standard deviation, chi square test and wilcoxon signed rank test.Results:The pre and post-test means value for group I while motion was 4.73and3.5, while standing 5.47 and 4.2, while sitting 6.37 and 4.73. The pre and post-test mean value for group II, while motion was 3.93 and 5.1, standing was 4.77and 5.67, while sitting 5.57 and 6.5. The obtained Wilcoxon value for group I was 4.944,4.916 and 4.969 during motion, standing and sitting respectively. The obtained Wilcoxon value for group II was5.152, 4.838and 4.613 during motion, sitting and standing. It was statistically significant at P value was˂ 0. 001.There is significant difference between the pre and post-testassessment score of reduction of backache in experimental group. The result shows that backstretch exercise was effective in reduceing low backache during antenatalperiod. CONCLUSION:The study concludes that backstretch exercise is effective on reduction of low backache among antenatal mothers. From this study, the backstretch exercise can be followed by all the antenatal ward nurses as evidence-based practice for low backache among antenatal mothers.