Over half of women after giving birth have low back pain (LBP), however, LBP is often accepted as a normal part of postpartum. Unsolved low back pain undoubtedly affects women's physical health and may be negatively affect their psychological health. This study was aimed to investigate the efficacy of laser acupuncture therapy (LAT) in postpartum LBP. Postpartum women with LBP admitted at a postpartum care center were recruited and randomly assigned to the intervention group or the control group. The participants in the intervention group underwent 10 sessions/2 weeks of LAT and received standard obstetric care. The participants in the control group only received standard obstetric care. Primary outcome measurements were Visual Analogue Scale (VAS) for pain and salivary cortisol values. Secondary outcome measurements were Chinese versions of the Roland and Morris Disability Questionnaire (RMDQ), Oswestry Disability Index (ODI) version 2.1and the Perceived Stress Scale (PSS).

Inclusion Criteria:

1. Age not less than 20 years
2. Women postpartum within one month
3. Low back pain with visual analogue scale (VAS) score ≧1
4. Low back pain was not relieved by rest for 30 minutes.

Exclusion Criteria:

1. with systemic diseases
2. with cancers
3. with psychiatric diseases
4. under treatment for severe pain by a physician.