During the last two decades, the public and private sectors have made substantial international research progress toward improving the nutritional value of a wide range of food and feed crops.  Nevertheless, significant numbers of people still suffer from the effects of undernutrition.  In addition, the nutritional quality of feed is often a limiting factor in livestock production systems, particularly those in developing countries.  As newly developed crops with nutritionally improved traits come closer to being available to producers and consumers, we must ensure that scientifically sound and efficient processes are used to assess the safety and nutritional quality of these crops.  Such processes will facilitate deploying these crops to those world areas with large numbers of people who need them.  This document describes five case studies of crops with improved nutritional value.  These case studies examine the principles and recommendations published by the Intl.  Life Sciences Ins. (ILSI) in 2004 for the safety and nutritional assessment of foods and feeds derived from nutritionally improved crops (ILSI 2004).  One overarching conclusion that spans all five case studies is that the comparative safety assessment process is a valid approach.  Such a process has been endorsed by many publications and organizations, including the 2004 ILSI publication.  The type and extent of data that are appropriate for a scientifically sound comparative safety assessment are presented on a case-by-case basis in a manner that takes into account scientific results published since the 2004 ILSI report.