From 1974 through 1976, U.S. Naval Medical Research Unit No. 5 isolated 25 strain of tick-borne virus in infant mice from 410 pools containing over 6,000 ticks, and one strain from a bird and one strain from a rodent collected in central and southern Ethiopia. Of these, 17 were identified as known viruses previously found in West Central and East Africa. There were 8 strains of Jos virus from Amblyomma ticks; 7 strains of Dugbe virus from a bird, a rodent and from ticks; 1 strains of Crimean-Congo hemorrhagic fever virus and 1 strain of Thogoto virus from ticks.