Stereoregular poly(N-isopropylacrylamide)s with controlled content of isotactic dyads have recently been synthesized, and interesting interference phenomena between LCST phase separation and high-temperature reversible gelation have been observed in their aqueous solutions. We develop a model solution in which dehydrated stereo-regular isotactic segments on polymers are driven into intermolecular cross-links leading to gelation. We theoretically calculate the phase diagrams for the varied content isotactic dyads and compare with the experimental data. (c) 2013 Elsevier Ltd. All rights reserved.