The use of performance information is the backbone of performance management. Performance information use refers to the willingness of public managers or other relevant stakeholders to incorporate quantitative or qualitative data in their decision-making. Both routine and nonroutine performance information is considered essential in managers’ decision making. Understanding the organizational factors that motivate public managers to use performance information is an important topic in the literature and practice of performance management. Although the number of studies on information use is growing, little is known about the impact of Organizational Social Capital (OSC). OSC is composed of the sub-dimensions of social interaction, trust, and shared goals. The main argument of this study is that OSC fosters performance information use in public administrations. It is expected that departments with high levels of organizational social capital are more likely to use both routine and nonroutine performance information. To test the hypothesized effect, department heads, middle managers, and other individuals with a supervisory role from 513 Florida County Government departments were surveyed. Furthermore, interviews, focus groups, and analysis of secondary data were performed to provide the context and the narrative surrounding the hypothesized effect. Analysis of the survey data reveals evidence in support of the hypothesized effects. Furthermore, the comparative case study analysis shows the existence of substantial differences in the history, background, organizational culture, and management between the two counties. The main findings show how reorganization processes as well as a lack of leadership may have detrimental effects to organizational social capital. Organizational social capital could be considered a relevant predictor of performance information use and thus deserves further attention from both researchers and practitioners.