Let R be a prime ring with extended centroid C. By a generalized derivation
of R we mean an additive map g: R --> R such that (xy)(g) = x(g)y + xy(del
ta) for all x epsilon R, where delta is a derivation of R. In this paper we
prove a version of Kharchenko's theorem for generalized derivations and pr
esent some results concerning certain identities with generalized derivatio
ns.