This paper examines the financial and operating performance of 31 national telecommunication companies in 25 countries that were fully or partially privatized through public share offering. Using conventional pre- versus post-privatization comparisons and panel data estimation techniques, we find that the financial and operating performance of telecommunications companies improves significantly after privatization, but that a sizable fraction of the observed improvement results from regulatory changes-alone or in combination with major ownership changes-rather than from privatization alone. (C) 2002 Elsevier Science Ltd. All rights reserved.