This article provides evidence that jatropha seed coat residues can be used as a carbon source for preparing activated carbons that have good adsorption properties for iodine and methylene blue. Activated carbons were prepared using three different methods of activation, physical, chemical, and physico-chemical, for a range of activation temperatures (600 degrees, 700 degrees, 800 degrees, and 900 degrees C) and activation hold times (1, 2, and 3 h). The highest BET surface area (1479 m(2) g(-1)) and the highest iodine adsorption (1511 mg g(-1)) were obtained with physico-chemical activation at a temperature of 900 degrees C and a hold time of 2 h. This activated carbon gave higher BET surface area and iodine adsorption than commercial activated carbon (1169.1 m(2) g(-1) and 1076 mg g(-1)). The activated carbons prepared by physico-chemical activation at 900 degrees C and 2 h were then tested for adsorption of methylene blue at a range of concentrations of methylene blue (100, 200, 300, 400, and 500 mgL(-1)). It was found that a Langmuir isotherm gave a better fit (R-2 = 0.999) to the observed adsorptions than a Freundlich isotherm (R-2 = 0.884). For the adsorption kinetics, a pseudo-second-order model gave a better fit (R-2 > 0.998, Delta q(e) = 3.7%) than a pseudo-first-order model (R-2 approximate to 0.95, Delta q(e) = 85.6%). These results suggest that chemisorption is the rate-controlling step for the adsorption of methylene blue. The experimental results show that jatropha seed coat is a lignocellulosic waste precursor for preparation of activated carbon that is an alternative source for preparation of commercial-grade activated carbons.