Preliminary studies have shown that diamond-like carbon (DLC) coatings can be adherent on a range of substrate materials, resistant to wear and non-toxic to cells in vitro. This has led to the question of the possible biomedical application of DLC-coated materials, particularly in the field of implantation surgery. Assessment of the biocompatibility of implanted material requires two questions to be addressed: (1) is the implanted material toxic to cell growth, and (2) what is the nature of the cell-DLC layer interaction? In this study we show, by the Kenacid Blue cytotoxicity test, that cells grown on DLC-coated PCF membranes exhibit an initial increased attachment to the carbon substrate, and thereafter exhibit a normal growth rate over the 3-day test periods compared with cells grown on uncoated polystyrene. Scanning electron microscopy shows these cells possess characteristics typical of normal cell attachment and growth. Cells were grown on DLC-coated PCF membranes to facilitate examination of the cell-DLC coating interface by transmission electron microscopy. These results show that cells grown on both DLC-coated and non-coated membranes presented normal morphological characteristics of attachment and growth. These findings indicate that the DLC coating is non-toxic in vitro and sustains normal cell growth.