The recognition of human activities in the field of video surveillance is attracting more researchers. This has led to various approaches and proposals using different methods and techniques. The growing interest in the surveillance has also led researchers to give importance to abnormal human activities in order to propose appropriate and dedicated techniques to this type of activities. Unfortunately, the made proposals until now in this new field are ineffective and are adapted from those dedicated for normal human activities with minor modifications. They also suffer from several limitations and inadequacies and are very restricted because of the very limited number of works and syntheses. Therefore, this paper is an overview which provides a synthesis and an analysis of the existing works on the recognition of abnormal activities in order to provide researchers with a general view on the state of the art and be a help to propose new approaches.