Six parental peanut (Arachis hypogaea L.) cultivars, representing a wide range in genetic diversity, and 15 F₁ diallel hybrids were field evaluated for combining ability and heterosis. The parental cultivars included two Spanish, two runner, and two Virginia market types. Estimates of general and specific combining abilities were highly significant for all ten characters studied: partial biomass, harvest index, total pod weight, total pod number, total seed weight, total seed number, seed per pod, weight per seed, weight per pod, and meat content. Cultivars varied in relative general combining ability for different characteristics. Crosses of Spanish x runner type parents showed the greatest specific combining ability and heterosis for partial biomass, total pod weight, total pod number, total seed weight, and total seed number. Small or negative heterosis was found for the other traits. Highly significant positive phenotypic correlations were detected among several of these ten traits. The largest significant correlations were between total pod vs seed weight, total pod vs seed number, and weight per pod vs seed. These data indicate the importance of parental evaluation for improving peanut yield and related characters.