This paper investigates the role played by public capital on the production level of Italian regions by specifically accounting for the quality of institutions. Our analysis, carried out over the period 2000–2019, benefits from a rich data set on public expenditures. This allows us to build the regional public capital stock by distinguishing among public institutions in charge of the investments and sectors of intervention. While controlling for several contextual variables (human capital, technological capital, and population density), the main results show that public capital has a positive and significant effect on production. Most interestingly, looking at Mezzogiorno's regions, public capital carried out by local institutions turns out to have a lower impact than in the rest of the Italian regions. On the other hand, central bodies in the South exhibit an impact higher than the average. Moreover, institutions' quality exhibits a positive and significant effect on regional economic performance. These results cast serious doubts about the local Southern administrations' capacity to effectively manage the National Recovery and Resilience Plan's enormous resources and the new European Union cohesion framework 2021–2027. Our results are also relevant for other European regions that, featuring structural traits similar to Southern Italian regions, are expected to face the same difficulties in managing public funding.