Query logs of a Web search engine have been increasingly used as a vital source for data mining. This paper presents a study on largescale domain-independent entity extraction from search query logs. We present a completely unsupervised method to extract entities by applying pattern-based heuristics and statistical measures. We compare against existing techniques that use Web documents as well as search logs, and show that we improve over the state of the art. We also provide an in-depth qualitative analysis outlining differences and commonalities between these methods. Categories and Subject Descriptors I.2.6 [Artificial Intelligence]: Learning—knowledge acquisition General Terms Algorithms Keywords entity extraction, query logs, data mining