Innovation fosters sustainable management and allows managers to achieve a competitive advantage. Understanding the mechanisms that explain innovation’s antecedents provides an important contribution to theory and practice. The purpose of this study was to assess the importance of human resources (HR) practices in developing trust-based cooperation, which facilitates organizational innovation. Using the foundation of the Shea and Guzzo model, the roles of HR mechanisms were investigated. This study analyzes how effective cooperation can increase innovation and how certain HR practices can help to nurture a trust-based work environment. The conceptual model was developed by drawing on social exchange theory (SET). An empirical analysis of the results of a survey conducted on telecommunications companies (n = 175) aimed to verify the conceptual model. Structural equation modeling was used to assess the data. The findings indicated that competency development opportunities, team interdependence, and group rewards were the most significant determinants of interpersonal trust. As a consequence, a trust-based team generates effective cooperation, and as a result organizational innovation is strengthened. This study was based on large-scale survey data and provides a comprehensive outlook on how to promote organizational innovation through HR practices. This is the first study linking HR practices with trust, collaboration, and innovation.