A novel halophilic archaeon, strain TL6^T, was isolated from Telega Lake, a hypersaline environment in Prahova county, Romania. Strain TL6^T was able to grow in media with a salt concentration of between 2.5 and 5.2 M, with optimum growth at a concentration of 3.5 M. The novel strain was able to grow at concentrations of 1 M MgCl₂ or less, with an optimum of 0.4 M Mg²⁺. Growth of the novel strain occurred between pH 6.0 and 8.5, with an optimum of pH 7.0–7.5. The G+C content of the total DNA was 63.7 mol%. The 16S rRNA gene sequence of the novel strain was most closely related to species of the genus Haloferax (97.3–99.3 % sequence similarity). The lipid profile of the novel strain corresponded to that of other species belonging to the genus Haloferax. A comparative analysis of the phenotypic properties and DNA–DNA hybridization between the novel strain and other species of the genus Haloferax strongly supported the conclusion that strain TL6^T represents a novel species within this genus, for which the name Haloferax prahovense sp. nov., is proposed. The type strain is TL6^T (=JCM 13924^T=DSM 18310^T).