The antifungal and antibacterial activities of a number of acetates of trialkyl- and triphenyl-substituted germanium, tin and lead have been investigated. All three groups contain active as well as inactive compounds. High activity was found for certain tin and lead compounds, whereas activity of the germanium compounds was much lower. The activity optimum in the three trialkyl series varied according to the nature of the central atom and the type of organism used. A possible reason for these differences and a probable mode of action of the compounds are discussed.