Background Low back pain is a ubiquitous health, problem and leads to majör problems. Low-energy laser biostimulation can be used to treat low back pain in last years.

Objectives The aim of this double-blind controlled clinical study is to evaluate the effectiveness laser and combined exercise + laser in patients with chronic low back pain.

Methods Forty patients with chronic low back pain randomly divided into two groups of 20 patients. 20 patients in the first group received low-energy laser + exercise treatment, other group received low-energy laser treatment alone. The parameters such as pain and muscle strength were assessed in all patients pretreatment and posttreatment. Pain measurement was done using the visual anologue scale. Muscle strength measurement (m. rectus abdominus, oblicus, hip abductors, hip adductors, extensors and internal rotators, knee flexors and extansors, foot flexors and extansors, and dorsal extansors) was done using the manual muscle strength testing.

Results Both groups demonstrated significant improvements visual analogue scale and rectus abdominus, hip adductors and abductors in posttreatment (p < 0.05), but no relative advantage was found for either group (p > 0.05).

Conclusion In conclusion, under the conditions of this study, low-energy laser stimulation plus exercise did not provide a significant advantage over exercise alone.