Objective To investigate the effect of galectin-3 (Gal-3) on the expression of B-cell lymphoma-2 (bcl-2), Bcl-2-associated X protein (BAX), and cysteine aspartic acid-specific protease 3 (caspase-3) during cerebral ischemia in a model of cerebral ischemia-reperfusion injury, and to provide an experimental basis for the pathogenesis of cerebral ischemia.Methods A total of 18 male Sprague-Dawley rats were given ischemic treatment for 1.5 hours followed by reperfusion to 24 hours to establish a model of middle cerebral artery occlusion, and then these rats were randomly divided into sham-operation group, ischemia-reperfusion (I/R) group, and Gal-3 RNA interference (siRNA) group. Real-time PCR and Western blot were used to measure the changes in the mRNA and protein expression of Gal-3, bcl-2, BAX, and caspase-3 in rat cerebral cortex.Results After cerebral ischemia-reperfusion injury, the I/R group had significant reductions in the mRNA and protein expression of Gal-3 (0.38 and 0.47) and bcl-2 (1.310 and 1.299) and significant increases in the mRNA and protein expression of BAX (1.41 and 1.55) and caspase-3 (1.076 and 1.155). After Gal-3 RNA interference, the siRNA group had significant reductions in the mRNA and protein expression of Gal-3 (0.24 and 0.14) and bcl-2 (1.014 and 1.058) and significant increases in the mRNA and protein expression of BAX (1.76 and 1.88) and caspase-3 (1.480 and 1.515).Conclusions Gal-3 may participate in the pathological process of cerebral I/R injury by upregulating the mRNA and protein expression of Bcl-2 and downregulating the mRNA and protein expression of caspase-3 and BAX.