The ATP-binding cassette (ABC) proteins are one of the largest evolutionarily conserved families. They are characterized by the presence of highly conserved nucleotide-binding sites (NBS). In the present study, we identified ABC genes in rodent Plasmodia. We queried the Plasmodium yoelii genome with the ABC signature motif and retrieved 15 contigs. Sequences were classified into seven ABC families by BLAST comparison. Conservation of the five signature ABC motifs in the P. yoelii contigs was examined by multi-alignment of the NBS. Expression of the ABC genes was examined during the blood stages of P. yoelii and P. berghei and the hepatocytic stages of P. yoelii. Our results with RT-PCR on total RNA from blood stages demonstrated the expression of 14 ABC genes in P. yoelii and ten in P. berghei. In P. yoelii hepatocytic stages, the expression of four ABC genes was detected.