This study was carried out in cocoa-based agroforestry systems in Mbam and Inoubou department, Center Region, Cameroon. The study aimed at assessing the plant species diversity, ecological services, and carbon sequestration potentials of diverse trees associated in cocoa agroforestry systems. Twenty-seven sampling plots of 100 × 20 m were established in cocoa agroforestry systems in three villages. Our results registered the occurrence of 238 plant species grouped into 16 families in the sampled area. Sterculiaceae, Burseraceae, and Moraceae were the three dominant families. The species richness and diversity that were assessed using the Shannon index were 0.62, 0.66, and 0.68, respectively, while using the Simpson index, they were 1.421, 1.409, and 0.349, respectively, for Mouko, Rionong, and Nyamsong 3. Carbon stock sink was also estimated at 92.03, 55.18, and 46.83 tC/ha. Our results indicate a high flora diversity in cocoa-based agroforests especially with respect to fruit trees where Tetracarpidium conophorum is introduced. The total amount of CO 2 /ha per village plots is estimated at 337.46, 202.32, and 171.71 tCO 2 / ha. Then, the ecological services that should be paid according to 10 US$ per ton of carbon are evaluated at 3374.6, 2023.2, and 1717.1 US$ to the owner of the selected farms.