Determination of steam quality by passing one or more laser beams through steam in a steam chamber and directly determining a total number of vapor molecules and a total number of water molecules based on absorption of radiation in the one or more laser beams by the water vapor phase and the liquid water phase in the steam. Specific volumes of water vapor phase and liquid water phase in the steam using the total numbers of water vapor and liquid water molecules are determined and the quality of the steam is calculated based on the specific volumes of the water vapor phase and the liquid water phase in steam. One embodiment comprises a narrow linewidth laser for measuring steam quality and another embodiment comprises multiple broadband lasers for measuring steam quality.