Smallholders in humid tropical zones have often prefered to extend their plantations by clearing primary or secondary tropical forest rather than attempt replanting. The two main advantages procured by tropical forest-low 'land rent' and substantial ¿forest rent' are verified in Indonesia and Côte d'Ivoire, in cocoa and rubber. The two rents logically tend to become reversed as the cycle proceeds. This reversal may create conditions that are more favorable for replanting, possibly through a land market. The technical, economic and social factors of the decision to replant or not to replant and then possible deterrninants in the 'monoculture/agroforestry' dualism are reviewed succinctly. Monoculture is a migrant's strategy and agroforestry that of autochthons or long-established migrants. From a technical point of view, agroforestry emerges as one of the conditions of sustainability in humid tropical zones and in particular for replanting. However, we are far from having seen the end of monoculture vith inputs, especially with regard to replanting. From a social point of view, land conflicts which coincide vith the replanting phase deserve a great attention as well as great cautiousness on behalf of policy makers.