Evaluate the effect of LLLT in the treatment of burning mouth syndrome (BMS). Twenty-one BMS patients were randomly assigned to two groups: 12 in the laser group (LG) and 9 in the control group (CG). Patients in the LG underwent 2-week sessions of LLLT for 4 weeks. The spot tip area of this tool is 0.088cm2, semi-conductor GaAlAs, with a wavelength of 808nm ±5nm (infrared), 200 mW output power, 1.97W/cm2 of power density, 3 J energy per point and application time 15 seconds per point. LLLT was applied punctually, in continuous emissions, on each of the sites where there was a symptom. Symptoms were evaluated with a visual analogue scale (VAS) and patient psychological profiles were assessed using the Hospital Anxiety-Depression Scale. No side effects were recorded. Statistical analysis was carried out via ANOVA and logistic regression analysis. The initial VAS score mean was 8.9 for the LG and 8.3 for the CG (p >0.05). After the eighth session the VAS score was 5.5 and 5.8 respectively, and at two months it was 4.7 and 5.1 respectively. Improvement variables were established by dichotomizing the pain scales. We obtained levels of significance for the improvement variable for the LG at the two-month follow-up (p=0.0038) and for the univariate analysis of the treatment. The improvement was marginally significant in the multivariant analysis of: dry mouth, dysgeusia, pain and the treatment (p=0.0538). LLLT may be an alternative treatment for the relief of oral burning in patients with BMS.