Côte d’Ivoire produces 40 % of the world supply of cocoa but much of the plantation area is aging and declining in productivity, while opportunities for land expansion into new forest land are quickly disappearing. Rejuvenation strategies for cocoa presently coalesce either around improved varieties and greater use of agro-chemical inputs in full sun systems or eco-certification that requires trees to be integrated with cocoa. Here, we explore the possibility of uniting these approaches through building on current farmer practice of incorporating trees in their cocoa fields to improve cocoa productivity and diversify their livelihoods. We interviewed 355 farmers about trees integrated in their cocoa fields across four locations in the South-West of Côte d’Ivoire in 2012, stratified by whether or not farmers were eco-certified. Despite the massive deforestation, a rich diversity of trees was found in cocoa fields and an overwhelming majority of farmers (95 %) wanted more trees and/or more tree species, regardless of their certification status or ethnic origin. There was a consensus that most trees were compatible with cocoa, but farmers also traded off negative impacts of some species against their productive contribution to their livelihood. Farmers valued tree diversity on their cocoa plots and provided detailed information on how 32 tree species interacted with cocoa in terms of soil moisture retention, soil fertility improvement and pest and disease interactions but also had key gaps in knowledge about alternative hosts of mirids and mistletoe. The majority of farmers were not aware of the certification requirements for tree species and shade cover but a much higher proportion of certified farmers (76 %) had received information about shade trees than non-certified farmers (15 %), although advice only related to eight tree species. Scope for building on local knowledge and practice to sustainably increase cocoa productivity through promoting tree diversity...