Introduction: Vascular and neuronal impairment is one of the reasons for early hospitalization of diabetic patients, mainly affecting the extremities of the lower limbs. Photobiomodulation is a non-pharmacological therapeutic line that has been increasingly used in recent years, and its effects are attributed to the modulatory capacity to increase the level of cellular energy metabolism. Objective: to evaluate the influence of photobiomodulation with light emitting diode (LED) in the red (V), infrared (IV) and associated (V + IV) spectrum on pain and blood flow in patients with diabetic neuropathy. Methods: The study sample consisted of 58 patients, aged between 45 and 70 years, totaling 116 evaluated lower limbs. The study procedure was carried out in 5 days. On the first day (pre-treatment), patients were assessed for vascular impairment and the level of neuropathic pain. From the second to the fourth day, photobiomodulation was applied directly to the skin of the patients' legs, using a blanket (33x42cm2) of red LEDs (620nm; 52.86 mW / cm²), infrared (940nm; 33.7 mW / cm²) or associated (620nm; 52.86 mW / cm² and 940nm; 33.7 mW / cm²) during 1'30 ". On the fifth day, patients underwent reassessment. Results: Regarding the assessment of neuropathic pain, there was an average reduction (p <0.05) between 4.7 and 5.5 points in the Douleur Neuropathique 4 Questions in all groups irradiated with LED, with a large clinical effect size. In the blood flow assessment, there were no statistically significant changes (p> 0.05), despite the moderate effect size. Conclusion: Photobiomodulation therapy with light emitting diode (LED) has been shown to be effective in relieving neuropathic pain in the lower limbs of diabetic patients, with a clinical effect in improving blood flow.