  Dilepton decays of pseudoscalar mesons have been drawing particular interest,
thanks to their sensitivity to both the QCD dynamics at low energy and also
signals beyond the Standard Model. In this context, we shortly review our
recent study on an improved Standard-Model prediction for the rare decay
$\pi^0\to e^+e^-$, and compare it with the first determination on the lattice
that predicted also the $\pi^0\to \gamma\gamma $ decay width as a byproduct. In
addition, we discuss our recent work on $K_L\to\ell^+\ell^-$ decays and its
connection to lattice QCD. We comment on the current uncertainty estimates and
discuss how they could be improved profiting from future experiments and
progress in lattice QCD.
