INTRODUCTION The treatment of varicose veins secondary to saphenous vein reflux has undergone a major shift in the past decade, primarily led by the introduction of less invasive techniques. Wavelengths of 810, 940 and 980 nm have higher rates of absorption by hemoglobin. Water chromophore is associated with an initial energy absorption peak at 980 nm, followed by peaks at 1500 and 2000 nm. The energy released into the vein lumen is therefore absorbed by water as well as by cellular and interstitial proteins. In contrast, laser beams with longer wavelengths act more specifically on water absorbance, resulting in less energy expenditure, such as in the case of the 1470-nm diode endolaser. An endoluminal energy density (LEED) around 50-160 J/cm has been demonstrated to effectively lead to venous occlusion, although LEEDs above 100 J/cm can also be associated with higher complication rates. In contrast, the 1920-nm diode laser is more specific for water and hemoglobin chromophores, tissue absorption at this wavelength being at least 2.5 times greater than the one obtained with the 1470-nm laser. It is therefore expected that less energy would be required to generate the same amount of venous closure.