  I discuss low energy aspects of heavy meson decays, where there is at least
one heavy meson in the final state. Examples are $B -\bar{B}$ mixing, $B \to D
\bar{D}$, $B \to D \eta'$, and $B \to D \gamma$. %and $B \to D W $ (Isgur-Wise
function). The analysis is performed in the heavy quark limit within
heavy-light chiral perturbation theory. Coefficients of $1/N_c$ suppressed
chiral Lagrangian terms (beyond factorization) have been estimated by means of
a heavy-light chiral quark model.
