Abstract Cultivation of soybean cells in a medium containing fungal culture filtrate induced glyceollin biosynthesis and loss of cell viability. Most of the glyceollin was released into the medium. Purified fungal cell walls (100μg/ml) and x 2 diluted fungal culture filtrate caused similar levels of glyceollin synthesis in soybean cell suspensions. Fungal culture filtrate treated cells, however, were dead after four days of culture, whereas, loss of cell viability in the case of 100μg/ml fungal cell wall treated cells was gradual. Culture filtrate-induced glyceollin production was not lethal to all cells if the cells were rinsed 24 hr after treatment. Toxic fungal products may be involved in this cell death. Addition of glyceollin to cell cultures, at amounts comparable to that produced in these studies, caused loss of cell viability but the surviving cells gradually regrew. Live cells caused the disappearance of glyceollin from the medium but autoclaved, glyceollin-treated cells had no effect on the added glyceollin even after 24 hr. Evidently, glyceollin was catabolized or bound only by living cells.