Ranitidine is a drug responsible for disturbing the microbial ecology of surface waters. The potential use of live activated sludge (0.5 g and 1.0 g) for removal of ranitidine, one of the most widely used H-2-receptor antagonists, from aqueous solution was examined. The bisorption of ranitidine on live activated sludge was investigated in a batch system. The ranitidine bisorption was fast and equilibrium was attained within 10 min. Data obtianed from batch studies applied to Langmuir, Freundlich, Tempkin isotherm models. Kinetic and equilibrium adsorption data show that the process obeys to the pseudo-second order kinetic equation, Freundlich and Tempkin adsorption models. Gribbs free energy values were found to be 4.588 kj/mol for 0.5 g adsorbent and 3.613 kj/mol for 1.0 g adsorbent and indicating the not spontaneity of the system. Octanol-water partition coefficient (K-ow) and bisorption coefficient, K-d, which describes the solid liquid partitioning charracteristics of a compound in biosorption mechanism were also calculated.