We organized a machine translation (MT) task at the Seventh NTCIR Workshop. Participating groups were requested to machine translate sentences in patent documents and also search topics for retrieving patent documents across languages. We analyzed the relationship between the accuracy of MT and its effects on the retrieval accuracy. Categories and Subject Descriptors H.3.1 [Information Storage and Retrieval]: Content Analysis and Indexing; H.3.3 [Information Storage and Retrieval]: Information Search and Retrieval; I.2.7 [Artificial Intelligence]: Natural Language Processing General Terms Measurement, Performance, Experimentation Keywords Cross-lingual information retrieval, Machine translation, Patent information, Evaluation measures, NTCIR