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 a deep exploratory spatial analysis based on several global indicators of spatial dependence. As a result, in a second step, while controlling for the extent to which the specialization of production in certain sectors influences the specialization of innovation, this paper analyses the role which geographical knowledge spillovers play in innovation concentration in some industries. In other words, after the geographic concentration of production has been controlled for, we address the role that the development of technologically specialised clusters in neighbouring regions may play. The analysis is based on an original statistical databank set up by CRENoS on regional patenting at the European Patent Office spanning from 1978 to 2001 and classified by ISIC sectors (3 digit) and on the Cambridge Econometrics database on production activity