Carbon-in-pulp is the preferable technique for the recovery of gold from thiourea solutions. However, the underlying process fundamentals are still poorly understood. This paper discusses the kinetics of gold adsorption from thiourea solution onto activated charcoal, type YH-15, prepared from apricot pits. The influence on the rate of gold adsorption of a number of parameters, time, temperature, pH and the concentrations of gold and free thiourea have been examined. There are three gold complexes present in thiourea solution namely: AuTu + , AuTu 2 + and AuTu 3 + . In a “natural” solution (unadjusted pH) the complexes AuTu + and AuTu 2 + are the ones which are principally adsorbed by charcoal. It is postulated that increased gold adsorption would result from the addition of acid to the thiourea solution, as this would increase the number of activated gold complexes at the charcoal surface. It would also increase the percentage of the total gold complexes having the lower coordination, that is, those complexes more readily adsorbed. Adding more thiourea should have the opposite effect. Based on this suggestion, an analysis of the combined influence of hydrogen ion and thiourea concentration upon the gold adsorption has been carried out and verified by experimentation. This paper also discusses the kinetic rate equation and its applicability. The derived rate equation was able to predict the experimentally observed adsorption behaviour with time at 40°C if the initial gold concentration was known. The adsorption rate increased with temperature and an activation energy of approximately 61 kJ/mol was calculated. This was taken as evidence that the adsorption rate is probably controlled by a chemical adsorption step.