In this article we analyse whether university-industry relations (UIR) work to inhibit university researchers' scientific productivity. We find that UIR exercise a positive effect on university scientific productivity when they are based on the development of activities with high scientific content, but only up to certain level. Also, we find that researchers that combine research and UIR activities obtain higher funding from competitive public sources than those that only engage in research. In addition, their average scientific productivity is higher and they achieve higher status within the institution than those members of faculty that concentrate only on research.