Crossing the Chasm is a marketing book by Geoffrey A. Moore that focuses on the specifics of marketing high tech products. It was first published in 1991.

Moore's theory is built on the idea that the rate of diffusion in the Technology Adoption Life Cycle curve is not continuous in high tech markets (see diagram below). Moore borrowed his diffusion of innovations theory from Everett Rogers, but argued that there is a chasm between the early adopters of the product (the technology enthusiasts and visionaries) and the early majority (the pragmatists). This is because visionaries and pragmatists have very different expectations. Moore exposes those differences and builds from there to suggest techniques to successfully cross the chasm, including choosing a target market, understanding the whole product concept, positioning the product, building a marketing strategy, choosing the most appropriate distribution channel and pricing.

The book is very accessible and not written just for marketing specialists. In 2002, 10 years after the first publication, more than 300,000 copies had been sold. Crossing the Chasm is available in several prints, one is ISBN 0060517123.

G.A. Moore, not to be confused with G.E. Moore or Gordon E. Moore, the originator of Moore's law of technology change.