U posljednjih 20 godina nanofluidi su privukli pažnju znanstvene zajednice te se broj radova na temu nanofluida tijekom godina znatno povećao. Povećana toplinska vodljivost fluida uslijed dodatka nanočestica osnovno je svojstvo koje je potaknulo intenzivno istraživanje nanofluida. S obzirom na to da u industriji uvijek postoji težnja poboljšanju učinkovitosti proizvodnih procesa, pa tako i procesa hlađenja procesnih struja, povećana toplinska vodljivost rashladnih fluida otvara mogućnosti za postizanje navedenog cilja. U ovom radu dan je pregled metoda priprave nanofluida te opis parametara koji utječu na njihovu toplinsku vodljivost. Dan je i osvrt na modele kojima se opisuje toplinska vodljivost nanofluida te pregled mogućih mehanizama koji doprinose povećanju njihove toplinske vodljivosti.; Nanofluids have attracted the attention of the scientific community during last twenty years and the number of papers on nanofluids has increased significantly as a result. The increased thermal conductivity of the fluid due to the addition of nanoparticles is a basic feature that has raised intensive research on nanofluids. Considering a permanent urge in the industry to improve efficiency of production processes, including the cooling streams of processes, the increased thermal conductivity of cooling fluids opens the possibility of achieving that goal. This paper provides an overview of nanofluid preparation methods and a description of parameters that affect the thermal conductivity of nanofluids. Also, the overviews of few models that describe the thermal conductivity of nanofluids as well as of possible mechanisms that contribute to the increase in thermal conductivity of nanofluids are given.