Florunner and Southern Runner peanut (Arachis hypogaea L.) cultivars were evaluated for yield, market grade and seed infections by Aspergillus spp. following treatment with fungicide programs for control of peanut leaf spot (Cercospora arachidicola Hori and Cercosporidium personatum (Berk. & M. A. Curtis) Deighton) in field trials during 1989 and 1991. The fungicide treatments were: 1) nonsprayed control; 2) chlorothalonil 1.26 kg a.i./ha (seven total applications); 3) the same as treatment no. two except tebuconazole 0.25 kg a.i./ha was substituted for chlorothalonil at applications three and five in 1989; and 4) the same as treatment no. three except cyproconazole 0.23 kg a.i./ha, was used instead of tebuconazole in 1991. Yield, grade ($/m.t.), and total crop value ($/ha) were higher for both cultivars when treated with chlorothalonil and either tebuconazole or cyproconazole than when chlorothalonil was used alone. Southern Runner had significantly lower percent damaged kernels (DK) than Florunner. In addition, Florunner peanuts treated with either tebuconazole or cyproconazole had significantly reduced DK when compared to chlorothalonil alone. Other market grade factors were not significantly different (P<0.05) between cultivars when each was harvested at optimum maturity. Major colonizers of damaged kernels were Aspergillus spp., Fusarium spp., and Rhizoctonia spp. Fungicide treatment and cultivar effects on kernel colonization by Aspergillus flavus Link: Fr. varied between environments. Southern Runner had higher levels of A. flavus contamination in the undamaged kernels than Florunner in 1991, but not in 1989. Possible increased incidence of infection and colonization by A. flavus in Southern Runner require further study.