The aim of this research is to explore the effect that innovation, as a potential source of sustained competitive advantage and firm growth, has on the achievement of sustainable economic performance. In particular, this paper empirically examines the influence of four innovation forms (intramural R&D, extramural R&D, product innovation, and process innovation) on firms’ sustainable economic performance, considering the moderating effect of family involvement in management. To test the hypotheses, random-effects regression analyses are applied to a longitudinal sample of 598 Spanish private manufacturing firms throughout the 2006–2015 period. The results show a negative effect of intramural and extramural R&D on sustainable economic performance and a positive effect of process innovation on sustainable economic performance. Moreover, a reinforced relationship between process innovation and sustainable economic performance is also revealed when family involvement in management acts as a moderator. The findings make several contributions to research and practice.