SUMMARY None of four isolates of Olpidium brassicae (Wor.) Dang. (Olpidia I, 2, 3 and 6) transmitted the original strain of satellite virus (sv I). Two strains of satellite virus recently isolated (sv 2 and sv 3) were both transmitted, but sv 2 only by Olpidium 6 and sv 3 only by Olpidium 3. Hence different iso- lates of Olpidium seem to be specific vectors for different strains of satellite virus.