A survey was made of fungi occurring in the rhizosphere of Gros Michel banana in Panama and Costa Rica, and in a virgin forest soil from Costa Rica. A total of 33 genera and 47 species were isolated, among them Dictyostelium mucoroides, Sphaerostilbe repens, Staphylotrichum coccosporum, Delacroixia coronata and Aspergillus janus. The occurrence of these fungi in soils is discussed. Although some samples were taken from an area in which banana production had been abandoned because of Fusarium wilt, the wilt pathogen, Fusarium oxysporum f. cubense was not found in any of the areas sampled.