Background & Aims: The aim of this study was to assess the effect of core stabilization exercise on the serum level of Activin A and back performance scale in elderly women. Materials & Methods: This study was a semi-experimental research. Eighteen volunteer women with low back pain (age 69. 1± 2. 45 years, body mass index 25. 5± 2. 84 kg/m 2 and fat percentage 33. 7± 2. 95%) were randomly divided into two equal groups (each with 9 individuals): experimental and control. Core stabilization training group performed the exercises 3 times per week, 60 minutes each time, for 8 weeks, while the control group was followed up. Body composition, Activin A levels, and back performance scale were measured in two groups before and after the intervention. Results: Ten weeks of core stabilization training significantly reduced Activin A serum level (from 5. 62 ng/ml to 2. 84 ng/ml) (p=0. 000) and improved back performance scale (from 58. 5% to 33. 3%) (p=0. 002) in elderly women with low back pain in the exercise group compared with the control group. Conclusion: Core stabilization exercise improves the back performance scale and reduces Activin A level in elderly women with low back pain.