This paper presents WikiTranslate, a system which performs query translation for cross-lingual information retrieval (CLIR) using only Wikipedia to obtain translations. Queries are mapped to Wikipedia concepts and the corresponding translations of these concepts in the target language are used to create the final query. WikiTranslate is evaluated by searching with topics in Dutch, French and Spanish in an English data collection. The systems achieved a performance of 67% compared to the monolingual baseline. Categories and Subject Descriptors H.3 [Information Storage and Retrieval]: H.3.1 Content Analysis and Indexing; H.3.3 Information Search and Retrieval; Keywords Cross-lingual information retrieval, query translation, word sense disambiguation, Wikipedia, comparable corpus