AbstractPoly-N-isopropylacrylamide (poly-NIPAM) is a water soluble nonionic polymer that exhibits a lower consolute solution temperature (LCST) of about 31°C. This paper describes the preparation and characterization of a monodisperse, hydrophilic polymer latex of poly-NIPAM, crosslinked by N,N'-methylenebisacrylamide. The presence of these crosslinking moieties will prevent dissolution of the particles at low temperatures; rather the particles will be swollen with solvent such that a microgel is formed. The swelling and rheological behaviour of the latex has been studied. The results show that at high temperatures the particles are ˜ 30 nm whilst at 25°C, the particles were ˜ 130 nm in diameter. This four fold increase in the particle diameter correspond to a ˜ sixty fold increase in volume. The rheological properties, both continuous and oscillatory shear, of these systems have also been studied and is strongly temperature dependant, reflecting the changes in phase volume of the NIPAM latex.