A comparatively simple and accurate equation of state has been developed for the liquid state. The proposed equation has the form where K and q are constants dependent on temperature. The equation is tested for validity against P‐V‐T data for aldehydes obtained in the course of this investigation. Literature data on alkanes, alcohols, and water were also utilized to confirm the validity of the equation. A critical comparison of the proposed equation with the Hudleston equation reveals the former to yield more satisfactory prediction of P‐V‐T behavior of liquids.