The purpose of this study is to observe the extent to which U.S.-listed foreign firms report non-GAAP financial performance measures and to compare the characteristics of these disclosures to those of U.S. firms. Using a matched-sample design, this research compares U.S.-listed foreign firm and U.S. firm non-GAAP disclosure frequency, non-GAAP disclosure adjustment characteristics, and reconciliation quality. Tests of the hypotheses indicate similar disclosure frequencies for U.S. firms and U.S.-listed foreign firms. Analyses of non-GAAP disclosure and adjustment characteristics provide evidence consistent with the interpretation that U.S. firms engage in aggressive non-GAAP reporting behaviors (reporting income-increasing adjustments and adjusting GAAP numbers with a greater magnitude and with a higher number of adjustments) equally or more so than U.S.-listed foreign firms. However, the quality of U.S. firm reconciliations to U.S. GAAP is equal to or greater than that of U.S.-listed foreign firms.