Of 67 dogs examined in 11 localities in Arbil Province, northern Iraq, 53 (79.1%) were found infected with Echinococcus granulosus. The infection rates in the 11 localities ranged from 66.7% to 100%. Infections were light (1-200 worms) in 37.7% of infected dogs, medium (201-1, 000 worms) in 20.8% and heavy (over 1, 000 worms) in 41.5%. The heaviest burden was detected in 13 dogs, in which 3, 000 to 8, 000 worms each were counted. Infection rates were slightly higher in male dogs (81.1%) than in bitches (76.7%) .