An effective Lagrangian for pseudoscalar, vector, and axial-vector mesons is used to calculate the electro-magnetic mass shifts of pseudoscalar mesons on the basis of vector-meson dominance. We show that a previously studied PVV interaction can give a significant negative contribution to δmK+-δmK0, at the same time implying an experimentally accessible enhanced decay rate for K*+→K++γ. On the other hand, the PVV contribution to the pion mass shifts remains small and does not alter the previously obtained good agreement with experiment. © 1969 The American Physical Society.