Exhibit 21 SUBSIDIARIES OF THE REGISTRANT NEXTLINK Communications, Inc. Jurisdiction of Organization - ----------------------------- ---------------------------- NEXTLINK Capital, Inc. Washington NEXTLINK Interactive, L.L.C. Washington NEXTLINK Leasing of Utah, L.L.C. Washington NEXTLINK Management Services, L.L.C. Washington NEXTLINK Mindshare, L.L.C. Washington NEXTLINK Pennsylvania, L.P. Washington d/b/a Penns Light Communications NEXTLINK Ohio, L.L.C. Washington NEXTLINK Solutions, L.L.C. Washington NEXTLINK Tennessee, L.L.C. Washington NEXTLINK Utah, L.L.C. Washington NEXTLINK Washington, L.L.C. Washington Telecommunications of Nevada, L.L.C. Washington