In this study I examined whether isoflurane, an inhalational anesthetic used commonly in clinical practice, affected glutamate uptake via glutamate transporters, proteins expressed in the plasma membrane of cells in the central nervous system. Isoflurane at clinically relevant concentrations (1-3%) caused a time-, sodium- and concentration-dependent increase of glutamate uptake in primary cultures of rat cerebral mixed glial cells. This enhancement was inhibited by a specific glutamate transporter inhibitor. The study also demonstrated that 2.0% isoflurane significantly increased both Vmax and Km of transporter-mediated glutamate uptake. Thus, isoflurane enhances glutamate uptake by a pathway that requires function of glutamate transporters. This represents a novel pharmacological effect of inhalational anesthetics and may contribute to isoflurane-induced anesthesia and neuroprotective effects.