A semiconductor package includes a substrate, a first chip stack on the substrate and including a first semiconductor chip, an underfill pattern on a first side of the first chip stack, and a second chip stack on the first chip stack and including a second semiconductor chip. The second chip stack is stacked so as to be offset to the first chip stack. The first chip stack includes a first adhesive layer under the first semiconductor chip and a first chip protection structure on the first semiconductor chip. The second chip stack includes a second adhesive layer under the second semiconductor chip and a second chip protection structure on the second semiconductor chip. An extension portion of the second adhesive layer is on one side of the first chip protection structure, and the underfill pattern extends from the first side of the first chip stack to the extension portion.