Abstract <p>Self-organization, specific electrical conductivity, UV absorption spectra, and fluorescence of aqueous solutions of ethyl alcohol with a concentration of 100 to 1 vol % are studied. It is shown that as the alcohol concentration decreases structural rearrangements, accompanied by nonmonotonic changes in the nature, size of the formed particles, and their percentage content, occur in solutions. It is found that structures with a size of hundreds of nm and a negative ζ-potential (domains) reach the highest content in the range of 60–30 vol % alcohol. In this range of alcohol concentrations, a relationship between the nonmonotonic concentration changes in the size of domains, their ζ-potential, specific electrical conductivity, and fluorescence intensity (<i>I</i>₃₄₀) is established, indicating that water–alcohol solutions behave as self-organized dispersed systems.</p>