Increasing population pressure and poor soil conditions threaten food-security in sub-Saharan Africa, which stresses the need for higher yields. Thanks to their ability to form symbiosis with N2-fixing bacteria legumes can act as an important source of nitrogen (N). N2-fixation is a process that is tightly regulated by various mechanisms and it can be influenced by a number of abiotic factors (temperature, drought, nutrient availability). Intercropping, the growing of two or more crops are grown at the same time, often includes legumes and fixed N can become available for other component crop. Possible pathways are 1. Mycorrhizal hyphal uptake and translocation, 2. Decomposition and decay of dead nodules, roots and above-ground litter in the soil or 3. Exudation of soluble N compounds by living cells. Other benefits of intercropping include better use of resources, both in space and time, as a result of niche differentiation. Interactions are not yet fully understood and research is often focused on specific circumstances. Better understanding could be achieved by focusing on underlying mechanisms. This knowledge could then be applied on a larger scale. Legume-Cereal intercropping seems to be suitable for increasing yields, especially under low-N circumstances often found in sub-Saharan Africa.