Abstract The protozoan Toxoplasma gondii is one of the most common infectious pathogenic parasites and can cause severe medical complications in infants and immune-compromised individuals. In the current study, Toxoplasma gondii was isolated from the placenta of aborted women and the suspension of placenta was inoculated into the peritoneal cavity of male and female laboratory rats. The acute toxoplasmosis in male and female laboratory rats was diagnosed using qReal-Time PCR and the ratio of diagnosis 96.55% in males and 98.85% in females. In chronic infection after two months of infection, the diagnostic rate was 100% in the males and females. The rate of diagnosis was 100% in male brain and in testis was 71.43%, while it reached 90.48% in female brain and 100% in ovary. The present study showed that the positive diagnosis of infection of Toxoplasma gondii in male and female rats infected experimentally by using the impression smear method for organs and stained with Giemsa, were 95.24% (42 / 40) in males and 100% (42 / 42) in females. The study also detected the load of DNA of the Toxoplasma gondii in blood samples (acute infection) and tissue samples (chronic infection) of experimentally infected male and female rats. Load of DNA of parasite in males with acute infection reached 0.65×104 and 8.76×104 in chronic infection (p <0.001), while in females, the load of DNA of parasite in acute infection reached 54.70×104 , while it appeared higher in chronic infection 437.00×104 (p <0.001). We carried out a rapid, sensitive, and quantitative real-time PCR for detection of T. gondii. The advantages of this technique for the diagnosis of toxoplasmosis in a clinical laboratory are discussed.