Purpose: The purpose of this study was to critically analyze important hygienic/secondary prophylactic and biomechanical aspects of removable partial denture (RPD) design. Materials and Methods: The literature related to traditional biomechanical design and open/hygienic design of RPDs was discussed by the authors at a 2.5-day workshop. The written report was circulated among the authors until a consensus was reached. Results: There is little scientific support for most of the traditional design principles of RPDs, nor has patient satisfaction shown any correlation with design factors. However, there is evidence that an open/hygienic design is more important than biomechanical aspects for long-term oral health. The biomechanical importance of some components is questioned, eg, indirect retention and guiding planes. Alternative connector designs that reduce risks of tissue injury are described. Direct retainers and pontics are discussed in relation to the possibilities they offer for gingival relief. Conclusion: Greater attention should be paid to RPD design principles that minimize the risks of tissue injury and plaque accumulation in accordance with modern concepts of preventive dentistry. Int J Prosthodont 2002;15:371–378.