The objective of this research was focused on identifying the determinants of innovation in the manufacturing industry of Peru. A quantitative research based on a non-experimental, correlational explanatory design was followed, using data from 1444 Peruvian manufacturing firms registered in the National Manufacturing Industry Innovation Survey (ENIIM 2015). We estimated a Tobit model for the innovation decision and the amount of investment in annual innovation. The main results showed a global and significant effect of a set of internal characteristics and external factors on the investment decision and the annual amount invested in innovation. Likewise, the size of the firm, the increase in the number of qualified workers, the existence of internal R&D infrastructure as well as the increase in innovation expenses from previous year and the private funds present a positive and significant effect on the propensity of innovation and on the annual amount invested in innovation. In contrast, the lack of competition in the sector have a negative influence on both the decision to innovate and the amount of investment in innovation. These findings contribute to discriminate the most relevant factors to stimulate the generation of Peruvian manufacturing innovation, contributing to the design of stimulus for more effective policies.