This research uses data from 2,470 not-for-profit-organizations (NFPOs) to examine the impact of organization size, risk, and complexity on monitoring costs in the NFP sector. OLS regression analysis indicate that monitoring costs are higher for (a) larger NFPOs, (b) NFPOs subject to the Single Audit Act, 8 NFPOs having larger amounts of assets tied up in receivables and inventories, (d) NFPOs spending a larger percentage of their expenses on program support services, and (e) NFPOs providing higher compensation to their officers and directors. In addition, some NFPOs such as schools and hospitals are associated with higher monitoring costs.