Access to public knowledge is a prerequisite for the good functioning of developed economies. Universities strive and are also requested to contribute to this knowledge both locally and internationally. Traditional studies on the geography of knowledge flows have identified a localisation effect; however, these studies do not use the country as the unit of observation and hence do not explore national patterns. In this paper, we hypothesise that the localisation of university knowledge flows is directly related to share of firm expenditure on research and development. To test this hypothesis, we use references to universities in patent documents as indicators based on a data set of around 20,000 university references, for 37 countries in the period 1990-2007. We build indicators for the university knowledge flows both inside and outside the applicant country, which we explain as a function of some proxies for national scientific size and structure based on econometric estimations. We draw some conclusions as to the importance of national business scientific strength for fostering increased domestic university knowledge flows.