Presents the proceedings of a conference on the classification of irregular varieties held in Trento, Italy, 1990. Amongst the topics covered are projective manifolds containing large linear subspaces and rational curves on Fano varieties.

M. Andreatta, E.Ballico, J.Wisniewski: Projective manifolds containing large linear subspaces; - F.Bardelli: Algebraic cohomology classes on some specialthreefolds; - Ch.Birkenhake, H.Lange: Norm-endomorphisms of abelian subvarieties; - C.Ciliberto, G.van der Geer: On the jacobian of ahyperplane section of a surface; - C.Ciliberto, H.Harris, M.Teixidor i Bigas: On the endomorphisms of Jac (W1d(C)) when p=1 and C has general moduli; - B. van Geemen: Projective models of Picard modular varieties; - J.Kollar, Y.Miyaoka, S.Mori: Rational curves on Fano varieties; - R. Salvati Manni: Modular forms of the fourth degree; A. Vistoli: Equivariant Grothendieck groups and equivariant Chow groups; - Trento examples; Open problems