The presence of nitrophenols in wastewater is of great environmental concern. Therefore, it is important to separate picric acid from wastewater streams. In this study, adsorption of picric acid was studied from aqueous solutions by using a weakly basic adsorbent (Amber lite IRA-67) at three different temperatures (298 K, 308 K, and 318 K). Adsorption of picric acid was investigated in terms of equilibrium, kinetics, and thermodynamic conditions. In the equilibrium studies, 1.00 g of Amber lite IRA-67 was determined as the optimal amount. The most used isotherms, Freundlich and Langmuir, were applied to the experimental data. The Langmuir isotherm gave good results with R squared values over 0.99 at different temperatures. In the kinetic studies, pseudofirst- and pseudosecond-order models and the Elovich equation were applied to the kinetic experiments. The pseudosecond-order model was fitted to this adsorption system with an R squared value of 0.996. In the thermodynamic studies, Delta H(ads)(0) = -21.204 kJ.mol(-1), Delta S(ads)(0) = -200.043 J.mol(-1).K(-1), and Delta G(ads)(0) for different temperatures were calculated.