Jute fiber was treated with various substituted benzene diazonium salts in the presence of various metal salts (CuSO4, NiSO4, K2Cr2O7, and KMnO4). It was found that metal ions were incorporated into the jute fiber along with the benzenediazonium salts. The quantity of metal (Cu, Ni, Cr, and Mn) in raw and treated jute fiber was determined using Flame Atomic Absorption Spectrophotometer (FAAS). The concentration levels of the elements Cu, Ni, Cr, and Mn in the raw fiber were found below the detection limit. However, the concentration of these metals in treated jute fiber was found much higher than the detection limit and are in the following order: Mn>Cr>Ni>Cu. The physico-mechanical properties of the raw and treated jute fiber was determined. It was found that the metal ions in the presence of o-hydroxy benzenediazonium salts imparts higher tensile strength to the jute fiber than the metal ions in the presence of p- and m-hydroxy benzenediazonium salts. © 2008 by The Haworth Press. All rights reserved.