The role of store-operated Ca² entry (SOCE) in the maintenance of sperm-induced Ca² oscillations was investigated in porcine eggs. We found that 10 μM gadolinium (Gd³ ), which is known to inhibit SOCE, blocked Ca² entry that was triggered by thapsigargin-induced store depletion and also caused an abrupt cessation of the fertilization Ca² signal. In a similar manner 3,5-bis(trifluoromethyl)pyrazole 2 (20 μM), and tetrapandin-2 (10 μM), potent SOCE inhibitors, also blocked thapsigargin-stimulated Ca² entry and disrupted the Ca² oscillations after sperm-egg fusion. The downregulation of Stim1 or Orai1 in the eggs did not alter the Ca² content of the intracellular stores, whereas co-overexpression of these proteins led to the generation of irregular Ca² transients after fertilization that stopped prematurely. We also found that thapsigargin completely emptied the endoplasmic reticulum, and that the series of Ca² transients stopped abruptly after the addition of thapsigargin to the fertilized eggs, indicating that the proper reloading of the intracellular stores is a prerequisite for the maintenance of the Ca² oscillations. These data strengthen our previous findings that in porcine eggs SOCE is a major signaling cascade that is responsible for sustaining the repetitive Ca² signal at fertilization.