Nanoimprint lithography is a high resolution and low cost patterning technique. Many difficulties have been overcome from the process point of view. This article is dedicated to the resist pattern characterization when they are annealed above the glass transition temperature of the material. This approach may be directly transposed to imprint process optimization when the demolding scheme is performed above the glass transition temperature. Simple model describing shape evolution with temperature is proposed and correlation with demolding process is presented. The results showed that a stamp release well above glass transition temperature is possible and may slightly impact the initial imprinted shape. Furthermore, this work may be transposed to determine temperature evolution of polymer dynamic viscosity. (c) 2007 American Vacuum Society.