This volume comprises the proceedings of the Industrial Conference on Data Mining (ICDM 2009) held in Leipzig (www.data-mining-forum.de). For this edition the Program Committee received 130 submissions. After the pe- review process, we accepted 32 high-quality papers for oral presentation that are included in this book. The topics range from theoretical aspects of data mining to app- cations of data mining, such as on multimedia data, in marketing, finance and telec- munication, in medicine and agriculture, and in process control, industry and society. Ten papers were selected for poster presentations that are published in the ICDM Poster Proceedings Volume by ibai-publishing (www.ibai-publishing.org). In conjunction with ICDM two workshops were run focusing on special hot app- cation-oriented topics in data mining. The workshop Data Mining in Marketing DMM 2009 was run for the second time. The papers are published in a separate workshop book "Advances in Data Mining on Markting" by ibai-publishing (www.ibai-publishing.org). The Workshop on Case-Based Reasoning for Multimedia Data CBR-MD ran for the second year. The papers are published in a special issue of the International Journal of Transactios on Case-Based Reasoning (www.ibai-publishing.org/journal/cbr).