In this paper we describe a system for automatic detection and recognition of trademarks in sports videos. We propose a compact representation of trademarks based on SIFT feature points and a matching algorithm to robustly detect and retrieve trademarks in a variety of different sports video types. Trademark localization is performed through robust clustering of matched feature points in the video frame. A supervised machine learning approach is used to automatically adapt the similarity threshold used to assess the trademark matches. Experimental results are provided, along with an analysis of the precision and recall. Results show that our proposed technique is efficient and effectively detects and classifies trademarks.