A new quartic equation of state (EOS) based on a general form is proposed. Parameters in the new equation are regressed as substance-specific constants for 88 pure substances. The calculated saturated properties for nonpolar and polar substances are compared with experimental data and with that obtained by the Peng-Robinson Stryjek-Vera (PRSV), Patel-Teja (PT), and Yun EOSs for the various pure substances. Despite its simplicity, the proposed equation has good predictive capability over the entire temperature region.