The 2008 edition of the Passive and Active Measurement Conference was the ninth of a series of successful events. Since 2000, the Passive and Active M- surement (PAM) conference has provided a forum for presenting and discussing innovative and early work in the area of Internet measurement. PAM has a tradition of being a workshop-like conference with lively discussion and active participation from all attendees. This event focuses on research and practical applications of network measurement and analysis techniques. This year’s coference was held in Cleveland, Ohio. PAM2008’s call for papers attracted 71 submissions. Each paper was ca- fully reviewed by at least three members of the Technical Program Committee. The reviewing process led to the acceptance of 23 papers. The papers were - ranged into eight sessions covering the following areas: addressing and topology, applications, classification and sampling, measurement systems andframeworks, wireless 802.11, tools, characterization and trends, and malware and anomalies. We are very grateful to Endace, Intel and Cisco Systems whose sponsoring allowed us to keep low registration costs and also to offer several travel grants to PhD students. We are also grateful to Case Western Reserve University for sponsoring PAM as a host.