Departing from a number of theoretical perspectives from which rationales for science, technology and innovation (STI) policy can be extracted, this paper discusses three questions. First, what rationales for public intervention can be derived from different economic theories, including theories usually associated with spatial dynamics and territorial relationships? Second, what policy instruments or policy-mixes can be associated with the various rationales? Third, what do these theories and associated rationales tell us about the territorial level or levels at which STI policies can usefully be designed and implemented? © 2008.