Information and communication technologies (ICT) have been initially used mainly for supporting or automating firms’ pre-existing business processes, in order to improve their efficiency. Subsequently it was realised that much more value can be generated from ICT if we exploit their great potential to drive innovations in firms’ products/services and processes. However, limited empirical research has been conducted concerning the effects of the many different types of enterprise systems (ES) that firms use on their innovation performance. This paper contributes in this direction. It investigates empirically and compares the effects of six important and widely used types of ES (ERP , CRM, e-sales, telework and collaboration support systems) on firms’ product/service and process innovation. Our study is based on a large dataset collected from 14.065 European firms through the e- Business Watch Survey of the European Commission, which has been used for estimating innovation models. We have been found that all examined types of ES have some positive effect on both product/service and process innovation; however, these effects differ in magnitude. Our results indicate that the e-sales are the strongest drivers of product/service innovation, followed by the CRM and external collaboration support systems; with respect to the process innovation the e-sales the strongest drivers of it as well, followed by the telework systems.