Capacity-building initiatives are popular among nongovernmental organizations (NGOs) worldwide. In response to a lack of valid and reliable capacity measures for NGOs working on various social issues, Shumate and colleagues developed an 8-dimension, 45-item NGO capacities instrument, based on data from U.S. NGOs. However, the proliferation of international research on NGO capacity raises questions about the degree to which such an instrument equally applies in other countries. To allow meaningful comparisons of NGO capacities across countries, we examine the measurement equivalence of this NGO capacity instrument across a matched sample of Chinese (N = 119) and U.S. (N = 150) NGOs. Findings suggest a new NGO capacity instrument, which comprises seven factors and 28 items and better accounts for the capacity of both Chinese and U.S. NGOs. Based on the new instrument, a series of comparative analyses highlight the influence of institutional factors on NGO capacities.