A multiplex reverse transcription polymerase chain reaction (multiplex RT-PCR) method was developed for the simultaneous detection and discrimination of three sweet potato potyviruses:Sweet potato feathery mottle virus (SPFMV), Sweet potato latent virus (SPLV) and Sweet potato virus G (SPVG). Three compatible sets of primers specific for each virus were designed in conserved regions of the coat protein (CP) gene for use in multiplex RT-PCR assay, and producing three distinct fragments 300, 420, and 600 bp, indicating the presence of SPFMV, SPLV and SPVG respectively. The individual RT-PCR assays and the multiplex assay were optimized for highest sensitivity and specificity. This study fulfilled the need for rapid and specific sweet potato potyvirus diagnostic tool and that also had the potential for investigating the epidemiology of sweet viral diseases.