Linezolid, the first of a new class of antibiotics, the oxazolidinones, is approved for treatment of Gram-positive bacterial infections, including resistant strains. Linezolid has a favourable pharmacokinetic profile. It is rapidly absorbed, when administered orally, and it is 100% bioavailable, thus allowing early switch from intravenous to oral administration. The maximum plasma concentration (range between 13.1±1.8 to 19.5±4.5 mg/ml) is achieved 1–2 hours after the first dosage. The level of plasma protein binding is 31%, and the volume of distribution approximates the total body water content (30 to 50 liters). It penetrates readily to most tissues of the human body at concentrations much higher than that of the minimal inhibitory concentrations of the targeted pathogens. It is metabolized by oxidation in two major inactive metabolites and is eliminated mainly through the kidneys. An optimal antibacterial effect is achieved when plasma drug concentrations are above the minimum inhibitory concentration (MIC) [TC>MIC] for the entire length of treatment and the ratio between the area under the plasma concentration-time curve (AUC) and the MIC (AUC/MIC) is greater than 100, as is most commonly obtained with administration of the standard dosage of linezolid 600mg twice daily.