  We compute the leading-order back-reaction to dilaton-driven inflation, due
to graviton, dilaton and gauge-boson production. The one-loop effect turns out
to be non-vanishing (unlike the case for pure de-Sitter and for power-law
inflation), to be of relative order $\ell_P^2H^2(t)$, and to have the correct
sign for favouring the exit to a FRW phase.
