Proceedings of the 9th Latin American Conference on the Applications of the Mössbauer Effect, LACAME 2004, held in Mexico City, Mexico, 19-24 September 2004. This volume demonstrates the way in which researchers, on a wide range of topics, many interdisciplinary, find the applications of the Mössbauer Effect an outstanding method whose results, sometimes unique, complements and improves the information obtained by other techniques to deepen the understanding of the matter under research. This volume comprises research papers, reviews, and short communications recording original investigations on applications to diverse areas like archaeology, metallurgy, soil science, geology, industrial applications, new instrumentation, corrosion, and chemical applications. The papers present the latest scientific work of various regional investigators and of the invited speakers from abroad that have brought their perspectives to the meeting.