Alongside a growing interest in nonprofit capacity building programs has come a growing concern with the impact of these programs, especially by organizations that fund them. This article describes how the McKinsey Organizational Capacity and Assessment Tool and, to a lesser extent, the Abt Associates survey have been used to assess changes in nonprofit capacity as part of nonprofit capacity-building programs. Drawing on field experience with both survey instruments in the context of a foundation-funded nonprofit capacity-building program, this article compares the respective benefits and costs of these instruments from the perspective of evaluators as well as survey respondents. Both perspectives are combined to offer guidance for organized philanthropy, particularly for foundations that are considering the incorporation of surveys into the design and evaluation of their nonprofit capacity-building programs. The more foundation leaders and evaluators can be aware of how survey instruments compare with one another, the better situated they will be to effectively integrate these tools into their capacity-building programs and, more broadly, their philanthropic practice.