Graphene nanosheets were prepared by pulsed Nd:YAG laser ablation of graphite target in H2O under ambient conditions. The synthesized graphene nanosheets were characterized by high resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD), Raman spectroscopy and Selected Area Electron Diffraction (SAED). The obtained structural and morphological analysis confirmed that the graphene nanosheets could be formed in an aqueous medium via one step method where a nanosecond pulsed near-infrared (NIR) laser (λ = 1064 nm) is used to ablate the surface of a pure graphite target. Compared to other used chemical methods to synthesis graphene nanosheets, laser ablation is an easy, versatile, environmental friendly and rapidly growing method for the synthesis of nanostructured materials such as graphene nanosheets. This technique showed normal operation in liquid medium (i.e. water or organic) under ambient conditions. Our study confirmed the great potential of laser ablation in liquid method for the fabrication of graphene nanosheets based nanofluids wich has a potential applicatiuon as a heat transfer fluid.