Purpose: In this research the effects of low power He-Ne laser irradiation were studied on osteosynthesis in rabbits from a biomechanical point of view. Study Design: Classic experimental. Materials and Methods: 60 white male Dutch rabbits underwent medial open dental hole partial osteotomy (DHPO) of the tibia bone under general anaesthesia and sterile conditions. In a later stage the rabbits were randomly divided into experimental and control groups. Each group with similar way was divided into three groups (14th, 21st and 28th days). The tibia of the experimental group received He-Ne laser radiation with 1.2 J/cm2 every day for 14, 21 and 28 days, while the tibia of control group served as a control. Measurements were done in the 14th, 21st, and 28th days after surgery. After this period rabbits were killed by ether and mechanical tests (three-point bending test) were done by a Zwick universal testing machine. The variables were: load deformation curve, F-Max, energy absorbed capacity, deformation, ultimate bending strength, force at elastic stage and force at segmental point. Data were analyzed by Student's t-test and ANOVA and multiple comparison tests. Results: Findings of mechanical measurement indicated that F-Max in the experimental group was significantly higher than control group at 28 days after surgery (P = 1.8 * 10-5 ). Energy absorbed capacity and ultimate bending strength were also significantly increased in experimental group. Conclusion: Low power He-Ne laser irradiation has been found to accelerate bone regeneration in rabbits.