Objectives: This study aims to verify whether red and infrared lasers can interfere with the healing process of wounds located at the point of application and at distance.

Materials and methods: Three circular wounds were conducted on the dorsum of rats, being one in the cranial region, another one in the medial region, and a third one in the caudal region. For this experimental study, 45 animals were investigated and divided into three groups, to which 15 animals were submitted to no laser of any kind, 15 animals were submitted to infrared laser, and 15 animals were submitted to red laser. The observation period was of three, five, and seven days. Thus, each group was divided into three subgroups (A, B, C) based on the observation period. For groups II and III the amount of energy during the irradiation was 8 J/cm ² , applied after the surgery and then every 48 h, totalizing, depending on the time of death of the animal, two, three or four irradiations.

Results: There was higher presence of edema in among 3 and 5 day period of analysis and acute inflammatory process were found in red laser irradiation study group. Quantitatively, there was no statistically significant difference in the percentage of reduction of wounds in and among the groups.

Conclusions: No statistical differences were found by the therapy with low power red and infra-red laser in the wound sizes during all period of analysis.