The Congo Basin is the second largest tropical forest in the world, spanning Cameroon, the Central African Republic, the Democratic Republic of the Congo, Equatorial New Guinea, Gabon and the Republic of Congo, yet the distribution of their carbon stocks and biomass is relatively unknown and remains highly uncertain. Given both the size of this region and the multitude of ecosystem services that tropical forests provide, this represents a critical gap in our understanding of the global forest system and of the global carbon cycle. Up to this day, a lack of ground-sourced inventory has limited our ability to understand and quantify these forests structures. Given the major logistical challenges in generating sufficient ground-sourced data in this remote, humid and politically unstable region, we propose the use of very high-resolution remote sensing techniques (optical, lidar, radar) in combination with strategic field verification excercises, as the most reliable approach to fill the gaps in our understanding of this critical forest region.