Fluoridated hydroxyapatite (FHA) discs with various fluorine contents have been used to study the effect of fluorine content on early-stage cell behavior. FHA powders with fluorine content in the range 0-0.577 (mol F /mol apatite) were pressed into discs and sintered at 1200°C for 1 hour. SAOs-2 rat osteosarcoma cells were cultured on each FHA disc and tissue culture polystyrene (control) with the same seeding density for 4 hours. The cell count was conducted using Alamarblue, and the morphology of cell attachment was observed using environmental scanning electron microscopy. It was apparent that the fluorine content in FHA had significant impact on the early cell behavior.