We show sharp Vizing-type inequalities for eternal domination. Namely, we prove that for any graphs G and H, c 1 ðG £ HÞ ! aðGÞc 1 ðHÞ, where c 1 is the eternal domination function, a is the independence number, and £ is the strong product of graphs. This addresses a question of Klostermeyer and Mynhardt. We also show some families of graphs attaining the strict inequality c 1 ðG w HÞ > c 1 ðGÞc 1 ðHÞ where w is the Cartesian product. For the eviction model of eternal domination, we show a sharp upper bound for e 1 ðG £ HÞ: