As an important component of the Rugose wood disease complex, Rupestris stem pitting (RSP) is the most prevalent viral disease of grapevines worldwide.  For many years, the etiology of the disease is not known.  The diagnosis of RSP has relied on a biological assay using the indicator Vitis rupestris “St. George”, a tedious and costly procedure that takes two to three years to complete. Much progress was made in the past decade.  A high molecular weight double-stranded (ds) RNA was first shown to be associated with RSP.  Cloning and sequencing of this dsRNA revealed a virus whose genome structure resembles those of potexviruses and carlaviruses.  The virus was designated Rupestris stem pitting associated virus (RSPaV) or Grapevine rupestris stem pitting associated virus.  Clear evidence demonstrates that RSPaV is not a homogeneous entity but is composed of a family of sequence variants.  Grapevine varieties are often infected with multiple sequence variants.  Phylogenetic analysis indicate that the genome of RSPaV is most closely related to carlaviruses except for a region encoding open reading frames 4 and 5, which seems more closely related to potexviruses.  Based on this finding, we suggest that RSPaV might have resulted from an ancient recombination event that occurred between a carlavirus and a potexvirus.  High levels of affinity prompted the authors to suggest that RSPaV, together with viruses from the genera Foveavirus, Potexvirus, Carlavirus, and possibly Allexivirus, be grouped into a new virus family.  Based on the nucleotide sequence information, reverse transcription-polymerase chain reaction assays were developed for the rapid detection of RSPaV.  The detection efficiency of RT-PCR varied depending on the primers used.  Polyclonal antibodies were produced against recombinant coat proteins of RSPaV that were expressed in bacterial cells.  Western blot and indirect enzyme-linked immunosorbent assays were developed for the successful detection of RSPaV.  Western blot asays revealed that the antigen levels of RSPaV in grapevine leaves fluctuate within the growing season.  These nucleic acid-and protein-based diagnostic methods are advantageous over the indicator indexing using “St. George”, because they are quicker, as reliable, more sensitive, and more suitable for large-scale assays.  The availability of the polyclonal antibodies also made possible the identification of RSPaV particles in grapevines that are infected with RSP.  Furthermore, clear evidence suggests that the indicator “St. George” plants are infected with a distinct isolate of RSPaV, whose genome differs extensively from the previously sequenced isolate.  In the end, directions for future research on RSPaV are discussed.