•We report a new low temperature solvothermal method to synthesize MoS2 nanomaterials.•The morphology of MoS2 solids depends on the electrolyte concentration (ionic strength).•Formation of MoS2 nanospheres occurs at low electrolyte concentration.•At higher electrolyte amounts, MoS2 nanotubes are preferentially formed. Different MoS2 nanostructures have been obtained following an innovative one-step solvothermal method by changing the concentration and type of the electrolyte while avoiding the use of surfactant. It was found that the chemical nature of the studied electrolyte ((NH4)2CO3 or KCl) do not significantly affect the morphology and structure of the obtained MoS2 nanomaterials. Nevertheless, increasing the electrolyte concentration yields to a remarkable modification of the morphology of the resulting MoS2 from nanospheres to worm-shaped then finally to nanotubes. All the obtained nanomaterials were characterized by X-ray diffraction, (XRD), transmission electron microscopy (TEM, HRTEM), Fourier transformation infra-red spectroscopy (FTIR), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS).