Cocoa is one main exported agricultural commodity in Cameroon, with a production estimated at 225,000 t/year. The sector is dominated by smallholders with an average of 1 ha/farmer. Traditionally cultivated under forest trees shade in complex agroforestry systems, full-sun cocoa plantations can now be observed in some regions. What is the influence of the agro-industries and exporting enterprises in the change of agricultural practices? Based on individual interviews of stakeholders all along the market chain: from the plantations to the exportation, this paper analysis the strategies and impacts of the industrial actors on the cropping practices of cocoa smallholders. The study involved interviews in Douala and Yaoundé of the downstream actors of the value chain, and focus group and individual interviews of farmers in the region Centre. It appears that industries mainly influence agricultural practices through certification.  Since 2000, the demand for certified cocoa has been growing. Industries developed certification programs to answer this demand; these programs usually involve smallholders cooperatives which are helped by a certification organism and an industrial partner to organize farming schools and teach the recommended practices to farmers. Smallholders are much demanded of this program, and queue to engage into a partnership with an industry. This type of partnership is perceived by smallholders as a mean to access technical advices, inputs, and to secure the quick sale of their production. Certification favors agroforestry practices and recommends maintaining a rich diversity of trees in cocoa plantations. Through this program, industries favour the continuity of agroforestry practices and promote sustainable use of inputs.