Many aspects of animal development are dependent on the dynamic release of calcium (Ca²⁺) ions. Although Ca²⁺ release within a cell is tightly controlled, how the release dynamics result in a specific biological output in embryonic development is less clear. The integration of pharmacological and molecular-genetic studies with in vivo imaging in zebrafish and Xenopus has linked endogenous Ca²⁺ release to the Wnt signaling network. Our data suggests that distinct Ca²⁺ release dynamics lead to antagonism of the developmentally important Wnt/ß-catenin pathway while sustained Ca²⁺ release modulates polarized cell movements.