The complete nucleotide sequence of the genomic RNA of bamboo mosaic virus (BaMV) was determined by sequencing a set of overlapping cDNA clones and by direct sequencing of the viral RNA. The RNA genome of BaMV is 6366 nucleotides long [excluding 3'poly(A) tail] and contains six open reading frames (ORFs 1 to 6) coding for polypeptides with M(r) values of 155K, 28K, 13K, 6K, 25K and 14K, respectively. The genome organization and sizes of the encoded proteins are very similar to those of other potexviruses which have been sequenced except that ORF 6 lies completely within ORF 1. The first five putative proteins of the BaMV genome show identities ranging between 44 to 59%, 26 to 49%, 30 to 53%, 15 to 35% and 20 to 30%, respectively, to the corresponding ORFs of other members of the potexvirus group. However the putative product ORF 6 shows no significant similarity to those of other potexvirus ORF products.