The data set collected with the ALEPH detector from 1991 to 1995 at LEP has been analysed to measure the charm forward-backward asymmetry at the Z. Out of a total of 4.1 million hadronic Z decays, about 36000 high momentum D ∗+ , D + and D 0 decays were reconstructed, of which 80% originate from Z→c c ̄ events. The forward-backward asymmetry was measured at three energy points: A FB c ( s =89.37 GeV)= −1.0±4.4 % A FB c ( s =91.22 GeV)= 6.3±1.0 % A FB c ( s =92.96 GeV)= 11.0±3.4 % . From this analysis, a value of the effective electroweak mixing angle sin 2 θ e ff W =0.2321±0.0016 is extracted.