The African green broadbill appears to have a widely varied diet, consisting of invertebrates such as small beetles, snails and insect larvae; and vegetable matter including small seeds, flowers, flower buds and fruits (2). It searches for food singly or in small flocks of up to ten birds (2). It will sit motionless on a perch, and then make quick short dashes back and forth after its insect prey, flying with vigorous regular wing beats, but achieving no great speed (3). The African green broadbill has also been seen climbing, like a woodpecker, up vertical branches and on the underside of horizontal limbs searching for invertebrate prey (2).
The nest of the African green broadbill is a remarkable structure; a ball woven from twigs, leaves and rootlets (4), 20 to 25 centimetres wide, with a side entrance (2). Layers of green lichen adorn the outside, and it is hung from a near inaccessible tree branch (2). Other information about its breeding is limited. Adult African green broadbills have been found in breeding condition in July and August, a fledged young was seen being fed by an adult in March, and a nest of chicks was found in April (2).