Compositions and methods are provided for the modulation of ras expression. Oligonucleotides are provided which are targeted to nucleic acids encoding human ras. Oligonucleotides specifically hybridizable with mRNA encoding human H-ras, Ki-ras and N-ras are provided. Such oligonucleotides can be used for therapeutics and diagnostics as well as for research purposes. Methods are also disclosed for modulating ras gene expression in cells and tissues using the oligonucleotides provided, and for specific modulation of expression of activated ras. Methods for diagnosis, detection and treatment of conditions, or particular cancers, associated with ras are also disclosed.