In this paper we attempt to provide empirical evidence on the phenomenon of cluster agglomeration of innovation activities throughout time and space in European regions. More specifically we try to assess whether there are some forces which support the development of technologically specialised regional clusters. In particular we want to determine the spatial extent of these forces, their dynamics along the eighties and nineties and their connection with production clustering. We have started from a mapping of innovation activity in European regions by means of an exploratory spatial analysis based on global indicators of spatial dependence. As a result, in a second step, we check the hypothesis that innovation concentration can be a result not only of the geographic concentration of production but also of the development of technologically specialised clusters in neighbouring regions. The analysis is based on a databank set up by CRENoS on regional patenting at the European Patent Office spanning from 1978 to 2001 and classified by ISIC sectors and on the Cambridge Econometrics database on production activity. Among the main results, it is shown that specialisation in innovative activity is positively and significantly influenced by specialisation in production activity. Additionally, it is obtained that innovation tends to cluster more in sectors in which the neighbouring regions are also technologically specialised