We study the eigenvalues of positive semidefinite matrix power products and obtain some inequalities, most of which are in terms of majorization. In particular, for A, B greater-than-or-equal-to 0, beta > alpha > 0, we prove log lambda1/alpha(A(alpha)B(alpha)) curly less than log lambda1/beta(A(beta)B(beta)). The result is a generalization of some work of Marcus, Lieb, Thirring, Le Couteur, Bushell, and Trustrum.