The mechanism of formation and structuring of composite coatings based on polyacrylate dispersions is studied in organic media of various polarities. Relationships for the regulation of dispersed-phase particle size during synthesis and aging and under phase-transition conditions are established. It is shown that with increasing degree of conversion of the polymerizing systems, particle size reaches a constant value at small conversions and then remains unchanged; the viscosities of the dispersions increase monotonically to constant values.