This book constitutes the refereed proceedings of the 14th International Conference on Passive and Active Measurement, PAM 2013, held in Hong Kong, China, in March 2013. The 24 revised full papers presented were carefully reviewed and selected from 74 submissions. The papers have been organized in the following topical sections: measurement design, experience and analysis; Internet wireless and mobility; performance measurement; protocol and application behavior; characterization of network usage; and network security and privacy. In addition, 9 poster abstracts have been included.