The potential of pine leaves as a low-cost biosorbent was investigated for removal of Basic Red 46 (BR 46) from aqueous solution. Various physico-chemical parameters were studied such as solution pH, biosorbent dosage, biosorbent size, dye concentration, temperature, contact time and ionic strength. Equilibrium data fitted well with the Langmuir isotherm model. The monolayer sorption capacity was found as 71.94 mg g(-1). Kinetic data were best described by the pseudo-second order model. Thermodynamic studies indicated that biosorption reactions were favourable and endothermic. Activation energy was calculated as 38.39 kJ mol(-1). These results demonstrated that the pine leaves could be used as a natural biosorbent for removal of BR 46 from aqueous solution. (C) 2011 Elsevier B.V. All rights reserved.