The aim of this clinical study was to compare low-level laser therapy (LLLT) switched on and switched off in the treatment of burning mouth syndrome (BMS). BMS is a debilitating condition for patients and highly demanding for physicians, characterized by burning symptoms in the oral cavity. Despite extensive research, so far only cognitive behavioral therapy and clonazepam have been proven successful for its treatment in randomized controlled trials. Forty-four patients with BMS were randomly assigned to the study laser group (LLLT) or the sham laser group. LLLT was performed with the GaAlAs laser (830 nm) used in non-contact mode on the site in the mouth where burning symptoms were present; study patients received 10 sessions (10 days). Each participant filled out the visual analog scale (VAS) and oral health impact on the quality of life scale (OHIP-CRO 14) before and after either therapy protocol. There were no significant differences between the groups before and after LLLT (switched on and off) in the quality of life (OHIP CRO 14 scores) (p>0.05). There was significant decrease in pain symptoms (VAS) in both LLLT switched on and LLLT switched off groups (p <0.05). Both LLLT switched on and switched off decreased pain symptoms (VAS) in patients with BMS; however, neither LLLT switched off or switched on im-proved the OHIP-CRO 14 scores.