During 1989 and 1990 over 200 000 hadronic and leptonic events, corresponding to about 8.5 pb-1 of data, were collected in a scan of the Z peak using the ALEPH detector at the e+ e- collider, LEP. These data, at the highest centre-of-mass energy available to date in e+ e- collisions, have allowed a broad range of searches for new particles and new phenomena to be performed in a mass range significantly higher than previously attainable. The searches performed by ALEPH for Higgs bosons, supersymmetric particles and leptoquarks, and for evidence of compositeness are reviewed. No positive signals have been observed but a comprehensive set of mass and coupling limits is presented. Branching ratio limits are given for a number of "rare" Z decays
