AbstractVery sensitive and accurate elastic light scattering (LS) measurements have been carried out on mixtures of water with methanol, ethanol, 1‐propanol and 2‐propanol. Methanol showed no particular effect, while ethanol, 2‐propanol and 1‐propanol showed signs of increasing cluster formation at a composition of 1 alcohol molecule to 5 water molecules. For the mixture of 1‐propanol with water, additional measurements of the quasielastic light scattering have been made and the hydrodynamic radii of the clusters have been calculated. This led to the suggestion of a cluster consisting of 8 1‐propanol molecules and a solvation envelope of about 40 water molecules. The concentration of this cluster was determined by elastic LS to be 83% of the total solution weight at 25°C and a composition of 40% by weight 1‐propanol in water. The clusters appear to be rather stable, as the hydrodynamic radius showed no significant variation with temperature in the 5° to 50°C range. The concentration was however temperature dependent, as could be shown with elastic LS.