This book constitutes the refereed proceedings of the Third International Workshop on Controlled Natural Language, CNL 2012, held in Zurich, Switzerland,  in August 2012.
The 12 revised papers presented in this volume were carefully reviewed and selected from numerous submissions. The papers are organized in topical sections on CNL for knowledge representation, CNL for interactive systems, CNL applications, CNL grammars and lexica, CNL in the context of the Semantic Web and Linked Open Data and CNL use cases.