Cationic poly(urethane-acrylate) emulsifier-free microemulsions are prepared by seeded emulsion polymerization (SPUA) or in-situ emulsion polymerization (IPUA) with (a) or without (b) crosslinking agent hydroxyethyl acrylate (HEA). Furthermore, no surfactant is introduced into the reaction system. The effect of continuous phase and HEA on the rheological behavior and properties of microemulsions are studied. The results show that IPUA using vinylmonomers as the continuous phase and with HEA (IPUAMB-b) has the highest ζ value, lowest coagulation ratio, smallest particle size of 48 nm and apparent core–shell structures. Rheological research has concluded that the zero-shear viscosity of IPUAB-b and IPUAM-b emulsion is 6.03×10² and 7.89 Pa·s, respectively, and presents pseudoplastic behavior. However, IPUAMB-b and SPUA-b display Newtonian behavior with η₀ of 0.136 Pa·s and 0.0823 Pa·s, respectively. PUA emulsions display similar rheological behavior when NMP is replaced by the mixture of MMA and BA.