Five morphologically different nanostructured molybdenum disulfide (MoS2) samples were prepared, namely: nanoparticles, nanorods, nanoplatelets, nanoflowers and porous. These structures were characterized using X-ray diffraction and scanning electron microscope analyses. Afterwards, the up gradation of heavy oil was carried out in the presence of aforementioned nanostructures of molybdenum disulfide as catalysts. The results of catalytic and non-catalytic hydro-processing were compared. It was found that catalytic hydro-processing, due to lower sulfur contents, led to a more efficient and environmental friendly procedure as compared to non-catalytic hydro-processing. Furthermore, aromaticity, aromaticity condensation and branchiness index were also determined. In addition, nuclear magnetic resonance analyses were presented for the product of catalytic hydroprocessing. The nanoparticle morphology of molybdenum disulfide, catalyst, exhibited better result, due to its higher surface area, as compared to other morphologies of molybdenum disulfide catalysts, i.e., nanorods, nanoplatelets nanoflowers and porous structures.