Activated carbons (ACs) are prepared from wild almond shells (AS) and coir pith (CP) using phosphoric acid as an activating agent. Various process parameters like acid concentration, impregnation ratio, activation temperature, and time are optimized for better iodine adsorption capacity and yield. The impregnation ratio and the activation temperature are found to be the key parameters governing the porosity, surface area, and the yield of AC. The Brunauer-Emmett-Teller (BET) analysis of ACs shows that the surface areas are 1133.25 and 1210.58m(2)/g with the yields of 32.8 and 40.7%, respectively, produced from wild AS and CP. The maximum adsorption capacities for methylene blue are as high as 788.88 and 708.33mg/g. The equilibrium data is best described by the Langmuir and the Temkin isotherm, while the adsorption follows second-order kinetics, indicating that the intraparticle diffusion is one of the rate-controlling steps.