Background: The recovery process of tendon injury is slower and results in weaker scar tissue. The increase in metabolism and the formation of new blood vessels in the tendon occurs in the tendon healing mechanism. Laser energy that hits the tissue increases the blood flow and lymph flow in the tissue. Purpose: This study aims to determine the effects of low energy laser therapy on the tendon healing process. Method: A total of 21 white rats were divided into three groups, i.e., G1 as the control group without additional therapy, G2 with the therapy in the inflammatory phase (day 3), and G3 with the therapy in the proliferative phase (day 8). G2 and G3 received the therapy for five days at a dose of 1 Joule. The experiment animals were terminated on the 21^st day for evaluation, and the obtained and collected data at the end of the study were compared and analyzed using ANOVA statistical tests. Results: The groups that received the treatment using a low energy laser experienced an increase in the average number of fibroblasts by 78.99% per visual field in G2, and 79.23% in G3 in comparison to the control group. Conclusion: The administration of low energy laser therapy to the Achilles tendon healing of white rats brings positive results with an increase in the average number of fibroblasts.

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