Nano fuels are smart signs in the applications of nanotechnology in fuels field for the improvement of fuel quality and properties, decreasing their hazardous emissions and carbon foot print during processing and combustion in fuels engines. The current article deals with studying the impact of incorporation of green magnetite nano particles (NPs) in light and heavy vacuum gas oil fractions named in this work as LVGO and HVGO respectively, produced in AKO Refinery for asphalt and lube oils, Kirkuk-Iraq, on some physicochemical properties of the fuels. The properties investigated are flash, smoke and sulfur content. The green NPs were added at different load (0.1–1.0 g/l) and dispersed by ultrasonication during heating at constant temperature 35 °C and sonication power and frequency for 30 min. The results obtained showed that a remarkable increase in flash and smoke point, and a decrease in sulfur compounds content with increasing the dose of NPs. Using 1.0 g/l NPs load, an average increase in the flash point of about 7 and 8 °C, and in smoke point 9 and 4 °C for LVGO and HVGO fraction respectively compared to the control samples. A good decrease in sulfur content of about 646 and 1115 ppm was recorded for the LVGO and HVGO respectively compared to control samples using 1.0 g/l NPs load. The estimated results corresponded to the use the relatively small amount of the incorporated green NPs open the gate to these eco-friendly NPs for nano fuels formulation and application to enhance the quality of the vacuum oil fractions produced in Kurdistan region refineries.