The aim of this study was to evaluate the effects of low-level laser therapy (LLT) in pressure ulcers (PU) in humans through a systematic review of randomized studies. The search includes the databases MEDLINE, PEDro, Cochrane CENTRAL, and Lilacs, as well a manual search until May, 2016. This included randomized clinical trials of LLT compared with other interventions, different types of LLT, LLT placebo, or control in the treatment of PU. The outcomes evaluated were the ulcer area, healing rate, and overall healing rate. The risk of bias was evaluated using the tool of the Cochrane Collaboration, and the results were analyzed descriptively. From the 386 articles identified, only four studies were included, with two LLT used with single wavelength (1: 904 nm vs. control and 2: 940 nm vs. 808 nm vs. 658 nm vs. placebo) and two LLT used to probe cluster. One study compared to different single wavelengths showed a significant 71% reduction of the PU and an improved healing rate in which 47% of PU healed completely after 1 month of therapy with the use of LLT with a wavelength of 658 nm compared with other lengths. The other analyzed wavelengths were not significant in the assessed outcomes. Significant results were observed in the use of LLT with a 658 nm wavelength, and no evidence was found for use of wavelengths above that for the treatment of PU. Therefore, we also found no evidence in the laser used to probe the cluster.Registration number: CRD42016036648.

Contextualization: Hypertension is a disease that essentially affects the balance of vasodilator and vasoconstrictor mechanisms, causing an increase in vessels blood pressure that may compromise tissue irrigation and cause damage to the organs. Cases may develop to a severe clinical