In present work, the banana pseudo-stem fiber was used as an adsorbent for the removal of harmful malachite green dye. Functional groups, morphology and crystallinity of the adsorbent have been determined using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM) and X ray diffractometer (XRD). Batch experiments were performed to observe the effect of pH, contact time, initial dye concentration, adsorbent dose and temperature on the adsorption. The adsorption process followed pseudo-second order kinetics and intra-particle diffusion rate model. Equilibrium data were fitted to Langmuir and Freundlich isotherm models. Gibb’s free energy change (
G°), enthalpy change (
H°) and entropy change (
S°) indicate the nature of process. The negative values of
G° and
H° show that the process is spontaneous and exothermic, respectively. The negative values of
S° show that the dye molecules are organized on the adsorbent surface in less randomly fashion than in solution.