Abstract Thermoelectric liquid cooling systems have been widely used to maintain the temperature of electronic devices due to their small size, compactness, and simplicity. A few of these cooling systems utilize the waterblock as a liquid heat exchanger. This study aims to determine the performance of a thermoelectric-based water cooling system in a commercial waterblock. The research was conducted in the laboratory using a 4x12 cm aluminium waterblock placed on the cold side of TEC1-12715. Three variations of thermoelectric placement have been carried out; at the inlet and outlet, in the middle, and the end of the waterblock. The temperature of the coolant and the flow rate of the cooled fluid are kept constant for these variations. The results showed that the thermoelectric position on the waterblock affected the rate of reduction in fluid temperature and the cooling system’s performance.