Three infectious bursal disease field viruses, identified as U28, 3212, and MISS and isolated in the early 1980s from the southeastern United States, were characterized both antigenically and genotypically. A panel of monoclonal antibodies (MAbs) was utilized in an antigen-capture enzyme-linked immunosorbent assay (ELISA) for antigenic characterization. The ELISA data indicated that U28 and the Delaware variants are antigenically related. The 3212 and the GLS variants were more closely related antigenically to each other than to other viruses analyzed. However, the MISS isolate reacted with MAbs that were specific for both classic and variant strains of infectious bursal disease virus (IBDV). Reverse transcription-polymerase chain reaction (RT-PCR) was used to amplify nucleotide sequences from the genome coding for the variable region of VP2 from IBDV field isolates U28, 3212, and MISS. Phylogenetic analysis of the deduced amino acid sequences revealed that U28 was most similar (98.3%) to the IBDV Delaware variants and that 3212 was most similar (97.1%) to the GLS variant. The MISS isolate was most similar (97.4%) to the classic 52/70 strain. Positive correlation occurred with the use of different methods to characterize IBDV isolates.