The effect of low intensity laser radiation in the treatment of acute and chronic pain is now established in many studies. Trigeminal
neuralgia is a pain passes through nerve’s branches and its trigger is located in skin or mucosa that could lead to
pain with a trigger stimulus. The pain involved branches of trigeminal nerve that sometimes has patients to seek the treatment
for several years. Nowadays different treatments are used for relief of pain that most of them cause tolerance and various
side effects. This paper reviews and summarizes scientific papers available in English literature published in PubMed,
Scopus, Science Direct, Inter science, and Iran Medex from 1986 until July 2011 about the effect of these types of lasers on
trigeminal neuralgia which is one of the most painful afflictions known. In different studies, the effect of laser therapy has
been compared with placebo irradiation or medicinal and surgical treatment modalities. Low-level laser therapy (LLLT) is a
treatment strategy which uses a single wavelength light source. Laser radiation and monochromatic light may alter cell and
tissue function. However, in most studies laser therapy was associated with significant reduction in the intensity and frequency
of pain compared with other treatment strategies, a few studies revealed that between laser and placebo group there
was not any significant difference according to the analgesic effect. Low-level laser therapy could be considered in treatment
of trigeminal neuralgia without any side effects