The present research provides information on the dye biosorption potential of chemically modified non-conventional biomass obtained from Pyracantha coccinea. A cationic surfactant hegzade-cylethyldimethylammonium bromide (HDEDMABr) was used as modification agent. Dye biosorption characteristics of modified biomass were explored by batch mode equilibrium studies, zeta potential measurements and FTIR studies. When compared with the dried natural biomass, modified biomass was found to have high biosorption yield for Acid Red 44 (AR44) dye. Kinetic measurements revealed that the biosorption equilibrium was established in about 40 min of contact time. The biosorption process could be explained by the pseudo-second-order kinetic model and also followed the intraparticle diffusion model up to 40 min, but diffusion is not the only rate controlling step. A comparison of the different isotherms indicated that the dye biosorption by using modified biomass was well described by the Langmuir isotherm model with maximum monolayer capacity of 105.0 mg dye g(-1) biosorbent. Calculated thermodynamic parameters of biosorption indicated the exothermic and spontaneous process. Good biosorption yields ranged from 73.32 to 87.44% were obtained in the presence of the different concentrations of salt in the biosorption medium. Our results revealed that this developed biomass system may be useful for the decolorization of reactive dye contaminated solutions. (C) 2010 Elsevier B.V. All rights reserved.