The majority of corn acres in Iowa are planted in “conventional” 30-inch row widths, with some farmers choosing to stay with the 38-inch row system. Questions often arise on the magnitude of yield penalty, whether there really is a yield penalty, or if there is actually a benefit to wider row corn in specific situations with today’s elite hybrids. Recommendations are difficult because current data do not exist. There also is growing interest in narrower row corn (20-inch) and any economical or environmental benefits associated with this practice. These two questions have created a need for more research involving modern hybrids and management practices. The objectives of this study were to (1) identify any row width benefits and (2) determine the optimum planting population for each row width. In addition to this site in 2000, this research was conducted at two other university research farms.