Aims: STIM1 is an endoplasmic reticulum (ER)- resident Ca²⁺ sensor that has recently been shown to regulate SOCE in different cell types, including lymphocytes, platelets, and skeletal muscle cells. The homologous protein STIM2 has been proposed to control basal cytosol and ER Ca²⁺ concentrations ([Ca²⁺]), making a minor contribution to SOCE in some non-neuronal cell types. We, therefore, aimed to clarify the role of STIM proteins in neuronal Ca²⁺ homeostasis under physiological and ischemic conditions. Methods: We performed fura-2 Ca²⁺ imaging in neuronal cultures extracted from cortical tissue of wildtype (WT), Stim1^-/- , and Stim2^-/- mice. Ischemia- like conditions were induced by oxygen-glucose deprivation (OGD). Results: Both, SOCE and basal cytosolic [Ca²⁺] were significantly reduced in Stim2^-/- neurons compared to WT cells. No such differences were seen in Stim1^-/- cells compared with respective controls. Store content, determined by ionomycin-induced Ca²⁺ release, was decreased in Stim2^-/- compared to WT neurons. OGD (for 1 h) induced a markedly stronger Ca²⁺ accumulation in WT than in Stim2^-/- cells. Conclusion: Our data demonstrate that STIM2, but not STIM1, is required for SOCE in cortical mouse neurons. STIM2 is critical for OGD-induced neuronal Ca²⁺ accumulation, suggesting an important role for SOCE in neuronal death during cerebral ischemia.