0To investigate of Dictyocaulus viviparus infestation In cattle and
buffaloes, the study were carried out on 356 feacal samples collected from 221 calves and 135 buffaloe calves. The infestation was observed only in six calves, buffaloes did not show any positive case. In the second phase of the study 470 cattle and 400 buffaloes, which were slaughtered at Urmia slaughter house were examined during 1997-1998. The examination of Kings for the parasite were carried out. The result indicated only one positive case in cattle (0.21%).