In recent years, increasing numbers of researchers have used dietary patterns to characterize the population’s diet and to examine associations between diet and disease outcomes. Many methods, primarily data-driven and index-based approaches, are available for characterizing dietary patterns in a population. These methods often show associations with different disease outcomes that are sometimes stronger than those seen in studies of individual nutrients. However, no one method of dietary pattern analysis is regarded as better than all the others; there is little consensus on which approach should be applied for any given purpose. The reproducibility and validity of dietary patterns have been called into question and may possibly depend on the nature of the diet assessment measure (food frequency questionnaire (FFQ), 24 hour recalls (24HRs), diet records (DR)) and the subjective decisions made by researchers during the analyses or during the development of an index. Two recent review articles highlight the diversity of dietary patterns research and the current need for greater attention to methodological issues. A workshop titled" Dietary Patterns: Challenges and Opportunities in Dietary Patterns Research," was held at Experimental Biology, April 1, 2006, to address the current advantages and limitations of the various approaches to studying dietary patterns, as well as to consider future research that may be necessary to determine the best uses of the different approaches. This manuscript summarizes the major topics discussed at this workshop.