The determination of Toxoplasma gondii prevalence in a variety of domestic birds is thought as a good indicator of distribution of T.gondii ooccyts in the environment. To verify the potential role of domestic birds in circulating toxoplasmosis in Iran , the present study was conducted in Mazandaran Provinces, northern Iran . Latex agglutination test (LA) antibodies were found in 25 of 58 free-ranging chickens (Gallus domesticus) and ducks (Anas sp.). Also, viable T. gondii was isolated from 7 of 25 seropositive chickens and ducks by bioassay of their brains and hearts into mice. Most of the isolated strains were avirulant to mice. Genotyping of T.gondii isolates using Multiplex PCR for 5 microsatellite markers indicated that 7 isolates were type III. In this study type II and III isolates and mixed genotypes were not found. This study showed that domestic birds could have a potential role in transmitting toxoplasmosis to humans in Iran .