This paper aims to analyse the effect of interaction with universities on firm?s innovation output, measured as the degree of novelty of product innovation. The analysis is based on a sample of 3257 manufacturing firms active in innovation activities located in Spain. In the analysis we distinguish between two types of interaction mechanisms: cooperation in innovation activities and outsourcing of R&D services. Using data from two waves of the Spanish innovation survey (2004 and 2007), we examine the effect of interaction in 2004 on subsequent product innovation in 2005-2007. The results show that neither the cooperation with universities nor outsourcing of R&D services to these agents has a significant effect on product innovation. In other words, for Spanish manufacturing firms the acquisition of knowledge from universities does not represent an important strategy to introduce new products into the market. In contrast, cooperation with customers and the acquisition of external R&D from other firms seem to be important innovation strategies, especially for those firms pursuing more radical innovations.