For a large class of non-uniformly hyperbolic attractors of dissipative dif
feomorphisms, we prove that there are no "holes" in the basin of attraction
: stable manifolds of points in the attractor fill-in a full Lebesgue measu
re subset. Then, Lebesgue almost every point in the basin is generic for th
e SRB (Sinai-Ruelle-Bowen) measure of the attractor. This solves a problem
posed by Sinai and by Ruelle, for this class of systems.