The objective of this study was to examine fluoride release, microhardness and cytotoxicity of three different types of restorative materials; giomer (Beautifil Ⅱ), composite resin (FiltekTM Z250) and glass ionomer (Fuji Filling LC). Samples were prepared as disk-shaped specimens with diameter of 10 mm and thickness of 1 mm. Fluoride release was measured using pH meter (920A, Orion, Boston, USA) every 24 hours for the first 7 days followed by measurement every week until the 28th day. The Vickers hardness measurement was carried out for the microhardness, while in vitro cytotoxicity test of agar diffusion test was carried out according to ISO 10993-5 and ISO 7405. The results showed that microhardness of FiltekTM Z250 was the highest, followed by Beautifil Ⅱ, and Fuji Filling LC, in order. All groups, except FiltekTM Z250 released most amount of fluoride during first 24 hours and the release level was decreased over time. Cytotoxicity test indicated that all experimental materials were mildly toxicity. This study confirmed the variability of fluoride release, microhardness and cytotoxicity in these restorative materials and therefore such features should be considered in clinical application.