Abstract Background Studies have demonstrated that elderly people with low back pain (LBP) may have poor postural control compared to healthy older adults. Poor postural control is associated with poor balance performance and a high risk of serious falls. A variety of training strategies are proposed for LBP therapy, particularly core stabilization training. But this treatment for older people with LBP remains unclear. Methods 31 participants were randomly placed in a core stability training group (TG, n = 15) and a control group (CG, n = 16). The participants in the training group were required to complete 4 sets of core stability training and conventional physiotherapy 4 times per week for 4 weeks, whereas the participants in the control group only completed physiotherapy 4 times per week for 4 weeks. Ultrasound imaging was used to measure transverse abdominal muscle (TrA) thickness before and after the intervention. A 10-cm visual analog scale (VAS), the Oswestry Disability Index (ODI), and mobility functions were applied before and after the intervention. Data are reported as the median and range and were compared using two-way repeated-measures ANOVA,t-tests and chi-squared tests. P < 0.05 was considered significant in all statistical tests. Results After intervention, there was a statistically significant difference in scores in the intervention group, especially for VAS, ODI, timed up-and-go,10-m walking and the four-square step test. TrA thickness was increased after core stability training, which was not observed in the control group. Conclusion Core stability training is an effective intervention for older women with LBP.