Restriction fragment length polymorphisms (RFLPs) have been suggested as molecular markers to facilitate improvement of agronomic traits in maize (Zea mays L.). The objective of this study was to evaluate the utility of RFLP data in elucidating heterotic patterns among maize lines. Eight maize inbred lines and their 28 singlecross hybrids werevaluated for grain yield at two Iowa locations in each of 2 yr in a randomized-complete block design. The diallel mating design permitted estimation of general and specific combining ability effects. Restriction fragment length polymorphism analysis of inbred lines included five restriction enzymes and five eDNA and 28 genomic clones distributed over the maize genome. Restriction fragment length polymorphism patterns of crosses were predicted from analysis of the inbred parents. Genetic distances between inbred lines were estimated as modified Rogers' distance (MRD). Grain yield and specific combining ability were significantly correlated with MRD for six of the 10 chromosomes. Dispersion of inbred lines and hybrids for RFLP allele frequencies was generally consistent with expectations based on known pedigrees. Results from this study suggest RFLP analysis as a potential alternative to field testing when attempting to assign maize inbred lines to heterotic groups.