In the present work, an experimental study was conducted to quantify the heat transfer coefficient of a liquid metal mixture including gallium, indium and tin (Ga-In-Sn) under various heat fluxes inside a compact heat exchanger equipped with rectangular micro-passages. The microchannel was fabricated from Cu/Zn alloy using computer numerical control machining (CNC) to provide a plausible heat transfer. The experiments were conducted at 200-350 degrees C and for peristaltic mass flow rate of 0.1-1.5 gr/s. Pressure drop and also temperature profile along with the length of the microchannel were constantly measured and it was identified that Ga-In-Sn eutectic had a plausible thermal response at temperatures >200 degrees C. Also, the pressure drop value decreased with an increase in the temperature of the system. Also, an increase in the temperature of the system improved the heat transfer coefficient, while friction factor slightly changed with the temperature of the system. For all the experiments, the thermo-hydraulic evaluation parameter was >1 reaching to 1.3 at the highest temperature (T = 300 degrees C) and for the largest peristaltic flow rate (G = 1.5 gr/s). Also, a rough comparison between the correlations developed for the liquid metals and the experimental data showed that the results were in a good agreement with the equation developed by Seban-Shimazaki. (C) 2019 Elsevier Ltd. All rights reserved.