Nanofluids are new generation heat transfer fluids and are preferred over conventional fluids for heat transfer applications. Nanofluids are characterised by their enhanced thermal conductivities, high energy density and better heat transfer capabilities than the base fluids without nanoparticles. Glycol based fluids exhibit an anti-freezing characteristics at sub zero temperatures and hence widely used in heat exchangers in cold regions. In the present experimental work, CuO nanoparticles of size less than 50 nm are suspended in the base fluid of propylene glycol-water (60:40 by volume) mixture, in the range of 0.025, 0.1, 0.4, 0.8 and 1.2% volume fraction and CuO nanofluids were prepared. The effective thermal conductivity of nanofluids for different particle volume concentration is measured at different temperatures of nanofluids. The experimental results obtained show that thermal conductivity of nanofluids increases with increase in temperature and particle volume concentration of nanofluids. The conductivity data obtained in present investigation are compared with conductivity models and correlations available in the literature.