Abstract: The concentration of voriconazole (VRC) is highly variable. Therapeutic drug monitoring is required to improve the clinical response and safety of VRC. The optimum concentration of VRC for clinical response and safety is controversial so far. Therefore, we reviewed the related literatures of the relationships between VRC blood concentration, efficacy and safety. Low concentration of VRC was frequently associated with a higher incidence of treatment failure, but the literatures of VRC prophylactic application was limited. Neurotoxicity usually appeared at high VRC concentration and could be decreased by lowing concentration of VRC. However, hepatotoxicity appeared to be associated with VRC blood concentration, but was still prevalent at low concentration. Further research may need to optimize the therapeutic range of VRC blood concentration.