In Indonesia, recorded in various regions of Indonesia reaches 60-80 % of woman who have low back pain during pregnancy and most pregnant of them complain of Low back Pain since 24 weeks of pregnancy to postpartum. Most pregnant women say if they do not intervene to deal with perceived LBP. Back Exercise is one of the movements of pregnancy exercise that is useful for adding stability to the body by improving the imbalance of back and front muscle work, increasing muscle strength, loosening stiffened muscles, reducing mechanical pressure on lumbar, improving posture and improving mobility of joints. The purpose of this study was to determine the effect of Back Exercise on Low Back Pain in pregnant women. This type of research is an experimental research using one pretestposttest group design. Sampling using purposive sampling technique with sample of 16 pregnant women of trimester II and III who had LBP at Wirobrajan Yogyakarta Public Health Center. The data were collected using a Numeric Rating Scale pain scale questionnaire. Data were analyzed using paired t test. The conclusion of this research that there is influence Back Exercise on Low Back Pain in woman pregnant.