Abstract-Alumina ceramic is a biocompatible material with high potential in bone implant applications. Due to this material lacks enough mechanical properties for this purpose, it is necessary to develop new composites of alumina matrix for bone tissue regeneration. In this paper, the effect of carbon nanotubes/alumina on cell viability in vitro was evaluated. Methodology: Vero cells were treated with 125-5000 μg/ml of alumina composite. After 72h, Hoechst staining and MTT assay (3 (4, 5 dimethyl-2-thiazoyl) -2, 5-diphenyltetrazolic)) were performed for measuring cell viability. Results and Conclusions: The alumina ceramic composite with carbon nanotubes did not significatively affect cell viability with low percentages of carbon nanotubes (0,5 and 1,0%) but a cytotoxic effect was observed with high doses of carbon nanotubes (1,5%). Biocompatibility properties of alumina ceramic composite with carbon nanotubes must be further explored in different in vitro cell models.