Transient hot wire method is considered a reliable and precise technique for measuring the thermal conductivity of liquids. The present paper describes a new transient hot wire experimental set-up and its initial testing. The new apparatus was tested by performing thermal conductivity measurements on substances whose reference thermophysical properties data existed in literature, namely on pure toluene and double distilled deionized water. The values of thermal conductivity measured in the temperature range 25 to 45 °C deviated +2.2% to +3% from the literature data, while the expanded measurement uncertainty was estimated to be ±4%. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 172063]