Phosphoglucomutase is a key enzyme of glucose metabolism that interconverts glucose-1-phosphate and glucose-6-phosphate. Loss of the major isoform of phosphoglucomutase in Saccharomyces cerevisiae results in a significant increase in the cellular glucose-1-phosphate / glucose-6-phosphate ratio when cells are grown in media containing galactose as carbon source. This imbalance in glucose metabolites was recently shown to also cause a 6 to 9-fold increase in cellular Ca²⁺ accumulation. We found that Li⁺ inhibition of phosphoglucomutase causes a similar elevation of total cellular Ca²⁺ and an increase in ⁴⁵Ca²⁺ uptake in a wild-type yeast strain grown in media containing galactose, but not glucose as sole carbon source. Li⁺ treatment also reduced the transient elevation of cytosolic Ca²⁺ response that is triggered by exposure to external CaCl₂ or by the addition of galactose to yeast cells starved of carbon source. Finally, we found that the Ca²⁺ over-accumulation induced by Li⁺ exposure was significantly reduced in a strain lacking the vacuolar Ca²⁺-ATPase Pmc1p. These observations suggest that Li⁺ inhibition of phosphoglucomutase results in an increased glucose-1-phosphate / glucose-6-phosphate ratio, which results in an accelerated rate of vacuolar Ca²⁺ uptake via the Ca²⁺-ATPase Pmc1p.