In this study, the Chicory leaf powder (CLP) was used as a native adsorbent to eliminate the Acid Blue 25 dye from aqueous media. The prepared native adsorbent was characterized by several techniques including the X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform spectroscopy (FTIR), Brunauer-Emmet-Teller essay (BET), and particle size analyzer (PSA). A collection of experiments was performed to distinguish the optimal conditions and to probe the effects of the different parameters such as initial concentration, contact time, adsorbent dosage, pH of solution, and temperature on the sorbent capacity. The attained optimal conditions for removal the Acid Blue 25 dye were pH = 3-4, contact time 50 min, dosage 0.1 g, and initial concentrations 10 (mg/L) at 30 °C. The adsorption data revealed that the adsorption procedure has more match with the Langmuir isotherm than others. The kinetic data were better fitted with the pseudo-second-order pattern with a trusty correlation coefficient. Finally, the thermodynamic parameters illustrated that the adsorption process is exothermal and spontaneous. Based on magnitude of the standard enthalpy change related to the studied adsorption, we may derive that the considered adsorption is physical adsorption.