The uptake of Mn2+ by S. cerevisiae at the expense of endogenous sources of energy depends on the stage of culture development and is maximum in the middle of the exponential phase. The ability of cells to take up Mn2+ is related to the content of intracellular K at all stages of growth and to the content of ATP during the exponential phase, but not to the content of PPi PPi. The uptake is inhibited by oligomycin (25 .mu.g/ml) by 50-85% and under anaerobic conditions by 10-50%, depending on the stage of growth, indicating the role of aerobic phosphorylation in the process. The uptake of Mn2+ is apparently associated with a hydrolysis of low MW polyphosphates and ATP and with the exit of K+ from cells.