Heterophase water-in-oil polymerizations of acrylamide have been conducted in the presence of blends of non-ionic stabilizers at moderate monomer concentrations (20%). The initial monomeric system is located outside the inverse-microemulsion domain, yet close to the inverse-macroemulsion/inverse-microemulsion phase boundary. A turbid, viscous and unstable dispersion is produced at the outset and during the intermediate stages of the polymerization. This evolves to an inviscid and non-settling system at high conversions. Transparent inverse latices can also be produced provided that the polymerizations are conducted semi-adiabatically. Small angle neutron scattering (SANS) studies of the initial monomer and reacting systems have found the latices to be particulate with a particle diameter of 150 nm, independent of conversion. The SANS intensities can be fitted using a polydispese spherical particles model. Therefore, these heterophase water-in-oil polymerization systems seem to follow an inverse-macroemulsion-like mechanism. The ‘hybrid inverse-microemulsion/inverse-macroemulsion’ polyacrylamides produced herein have a smaller radius of gyration in aqueous media relative to those produced by either solution polymerization or a true inverse-macroemulsion polymerization of the same weight-average molecular weight. This is likely due to a large number of intramolecular interactions, such as hydrogen bonds, which are induced by the collapsed nature of the polymer chains in the inverse-microemulsion droplets. The weight-average molecular weight, the radius of gyration and the particle diameter of the final latex are relatively independent of the polymerizations conditions such as initiator level, hydrophilic-lipophilic balance (HLB), temperature and physical changes occurring during polymerization. From a kinetic point of view, the molecular weights of these systems are controlled by transfer to monomer, while transfer to interfacial emulsifier is the polymerization rate controlling step. A reaction mechanism consisting of a number of elementary reactions has been proposed for these heterophase-water-in-oil polymerizations. Agreement with the experimental data is found to be good at different levels of initiator, HLBs and temperature. Despite the limitations of this heterophase water-in-oil polymerizations (the moderate emulsifier levels, low radius of gyration and its inability to increase the weight-average molecular weight beyond 10 6 daltons), this polymerization process can produce final latices that are transparent and non-settling with small particles (< 150 nm). This allows post-reaction chemical modification, e.g. by the Mannich reaction.