Bismuth oxide nanoparticles (Bi2O3 NPs) have gained a spot in the development of novel molecular probes for in vivo biomedical imaging. It exists in six polymorphic forms and each of them exerts with different stabilities according to its synthetisation temperature. The aim of this preliminary study is to determine effect of different synthetiation temperatures on cellular viability in vitro. One hundred µg/ml Bi2O3 NPs synthesised at 60, 90 and 120°C were characterised using scanning electron microscope (SEM) and their cytotoxicity was evaluated using cell viability assay (MTT assay) upon 24 hours exposure to Chang liver cells. Images captured by SEM showed an average diameter of 300 nm monoclinic-shaped with high crystalline formation of all three Bi2O3 NPs. MTT assay revealed increase in liver cell viability as the synthetisation temperature of Bi2O3 NPs increase. The outcomes suggested that synthetisation temperature of Bi2O3 NPs plays a role in cellular viability, hence predictive to the biocompatibility of these nanoparticles to be applied as in vivo radiographic contrast medium.