This book constitutes the thoroughly refereed postproceedings of the 6th Workshop of the Cross-Language Evaluation Forum, CLEF 2005. The book presents 111 revised papers together with an introduction. Topical sections include multilingual textual document retrieval, cross-language and more, monolingual experiments, domain-specific information retrieval, interactive cross-language information retrieval, multiple language question answering, cross-language retrieval in image collections, cross-language speech retrieval, multilingual Web track, cross-language geographical retrieval, and evaluation issues.