Dimensional stability of fiber board from lignocellulosic materials is a prime concern for efficient utility of the product. A number of methods have been used to improve the dimensional stability. These include the application of coating, oil, and wax treatments and chemical modification of lignocellulosic materials. A new process has been developed to minimize irreversible swelling (i.e., permanent fixation of compressive deformation of wood fiber through a hygrothermal treatment using in-built steam from moisture of compressed fiber at high temperature). This process has been applied on jute fiber for the evaluation of dimensional stability and vis-a-vis the mechanical and thermal properties of the fiber board made from the modified jute fiber. (C) 2000 John Wiley & Sons, Inc.