One hundred stray dogs were examined to determine the prevalence of Echinoccocus and other intestinal helminthes in Mashhad area , Khorasan province of Iran. Helminths were collected at necropsy ,by scraping the intestinal contents. The collected worms were classified by their morphological characteristics. The helminthic infection were detected in 91% of dog examined. The prevalence of were Echinococcus granulosus (22%). Eighteen (81%) of infected dogs had light (1-100) worm burden and 3(13%) and 1(4%) had medium (100-1000) and heavy (>1000) worm burden, respectivly.The heaviest infected dog in this study harbored 10,000 worms. The prevalence of infection in sex and age groups were not significant.The other intestinal helminthes were diagnosed as follow: Dipylidium caninum (41%), Taenia hydatigena (37%),Taenia ovis (8%), Mesocestoides lineatus (6%),Taenia multiceps(3%), Joyeuxiella echinorhynchoides (1%) and observed nematodes were Toxocara canis (37%),Toxoascaris leonina (6%) and Ancylostoma caninum (1%).There was no significant difference in parasite prevalence between male and female dogs.The prevalence of infection in three groups’ ages of dogs (3 months-2 years, 2-6 years and > 6 years ) were investigated. The highest prevalence of Toxocara canis and Dipylidium caninum infection were observed in 3 months to 2 years of dogs and in contrast, in Taenia hydatigena was in 6> years .

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