Experimental measurements have shown that trimethylamine N-oxide, TMAO, is able to stabilize the globule state of PNIPAM [Phys. Chem. Chem. Phys. 2016; 18: 31459], the same effect it has towards the native state of globular proteins. The TMAO stabilizing action is rationalized by means of the same theoretical approach used to address the entropic driving force and the effect of sodium salts, urea and tetramethylurea on PNIPAM collapse [Phys. Chem. Chem. Phys. 2015; 17: 27750; Phys. Chem. Chem. Phys. 2016; 18: 14426]. TMAO stabilizes the PNIPAM globule state because its addition to water causes an increase in the magnitude of the solvent-excluded volume effect, and only a small increase in the magnitude of the PNIPAM-solvent energetic attractions, since TMAO interacts preferentially with water. (C) 2017 Elsevier Ltd. All rights reserved.