The cloud points t_cp of aqueous solutions of ethoxylated monoalkylphenols, AF9-n (n = 8,9,10,12), were measured in the concentration (C) range of 0.25-40 wt.%. t_cp increased as C decreased at C < 1 wt.%. At 1 < С < 10 wt.%, t_cp changed insignificantly; Δt_cp/t_cp did not exceed 5%. Solutions transformed into the gel state at С > 10-20 wt.% and t_cp sharply increased. The dependence of t_cp on the length of the oxyethylene chains of ethoxylated nonylphenols at C = 1 wt.% can be described by the equation t_cp = b·ln(n-n₀), where n₀ = 6. The cloud points of aqueous solutions (C = 1 wt.%) of the ethoxylated nonylphenols were measured at different concentrations of NaI, NaCl, NaF, Na₂CO₃, and Na₂SO₄ salts. For all of these solutions, t_cp decreased in the presence of NaCl, NaF, Na₂CO₃, Na₂SO₄ and increased in the presence of NaI. To describe the dependence of t_cp on the salt concentration, the equation was suggested, where and t_cp are the cloud points of a neat aqueous solution of ethoxylated nonylphenols and of the solution in the presence of electrolytes, respectively.