Phase change materials (PCMs) are widely used in the field of thermal energy storage (TES) [1]. PCMs store the thermal energy of a phase change (typically fusion), called the “latent” heat of phase change, on heating, and then when cooled, they give off the stored heat by reversing the phase change. Low melting metals and eutectic alloys are relatively new class of PCMs. The main advantages of the low-melting metallic materials usage as PCMs are their high volumetric latent heat and high thermal conductivity [2,3]. Low-melting bismuth-based eutectic alloys are promising candidates for the middle range metallic PCMs with the operating temperature from 40 to 200 °C [2]. In this study melting temperature, latent heat of melting and thermal conductivity of the Bi-In, Bi-Sn and Bi-In-Sn eutectic alloys were experimentally investigated. Melting temperatures and latent heat of melting were determined by using differential scanning calorimetry (DSC). Thermal diffusivity of the investigated eutectic alloys was measured at room temperature by using xenon flash method on a Discovery Xenon Flash DXF 500 device. Based on the experimentally determined values of thermal diffusivity and the specific heat capacity values obtained by thermodynamic calculation, thermal conductivity of the investigated eutectic alloys at 25 °C was obtained. It was determined that among three eutectic alloys from the Bi-In system, Bi– 47.44 at. % In alloy has the highest melting temperature (110.7 C) and latent heat of melting (42.7 Jg-1 ) but the smallest thermal conductivity (8.1 Wm-1K -1 ), which is close to the thermal conductivity of pure Bi (8.2 Wm-1K -1 ). Obtained melting points, latent heat of melting and thermal conductivities for the Bi–66.33 at. % In alloy are 90.7 °C, 30.2 Jg-1 , 12.2 Wm-1K -1 and for the Bi–77.92 at.% In alloy are 73.8 °C, 21.8 Jg-1 , 19.9 Wm-1K -1 . For the Bi-Sn eutectic alloy measured values are 138.6 °C, 43.5 Jg-1 , 24.3 Wm-1K -1 and for the two eutectic alloys from the Bi-In-Sn systems 76.6 °C, 32.6 Jg-1 , 11.0 Wm-1K -1 and 60.8 °C, 25.4 Jg-1 , 17.1 Wm-1K -1 .