Small high technology firms are often regarded as a vehicle for economic growth. This paper considers theories of small firm innovation and the evidence from sectoral, regional and national case studies. Small innovative firms appear to have some common needs; an environment conducive to entrepreneurship; entrepreneurial and technical ability to translate new technologies into products for which a market exists; pleasant locations where R&D activity is concentrated and where there are clusters of skilled craftsmen and local suppliers of ancillary goods and services. Current policies to stimulate the generation and growth of small high technology firms are evaluated and some alternatives are suggested.