This study investigated the influence of pulsed low-level laser therapy (LLLT) on the healing of a third-degree burn in a rat model. Two third-degree burns (distal and proximal) were made in the skin of 74 rats. Rats were divided into four groups. In group 1, the distal burn received LLLT with laser switched off; in groups 2 and 3, distal burns were treated with a 3,000 Hz-pulsed infrared diode laser with 2.3 and 11.7 J/cm(2) energy densities, respectively. In group 4, the distal burns were treated topically with 0.2% nitrofurazone. The proximal burn of all groups was considered a control burn. We assessed the response to treatment both microbiologically and macroscopically. The chi-square test showed that the incidence of Staphylococcus epidermidis, Lactobacillus, and diphtheria decreased significantly in laser-treated groups compared with other groups. Independent sample t-test showed that LLLT with 11.7 J/cm(2) energy density significantly increased wound-closure rate at 3 and 4 weeks after burning compared with their relevant control burns (p = 0.018 and p = 0.01, respectively). Pulsed LLLT with 11.7 J/cm(2)/890 nm of a third-degree burn in a rat model significantly increased wound-closure rate compared with control burns.