This paper presents the results of ETISEO, a performance evaluation project for video surveillance systems. Many other projects have already evaluated the performance of video surveillance systems, but more on an end-user point of view. ETISEO aims at studying the dependency between algorithms and the video characteristics. Firstly we describe ETISEO methodology which consists in addressing each video processing problem separately. Secondly, we present the main evaluation metrics of ETISEO as well as their benefits, limitations and conditions of use. Finally, we discuss about the contributions of ETISEO to the evaluation community.