Current therapies against toxoplasmosis are limited and drugs have significant side effects and low efficacies. We evaluated the potential anti-Toxoplasma activity of propranolol 2, 3 mg/kg/day in vivo in acute and chronic phases. Propranolol as the stabilizing cell membrane is a suitable drug for inhibiting the entrance of Toxoplasma gondii (T. gondii) tachyzoites into cells. The acute phase was performed using propranolol, pyrimethamine, propranolol plus pyrimethamine before (pre-treatment) and after (post-treatment) intraperitoneally challenge with 1×103 tachyzoites of the virulent RH strain of T. gondii in Balb/c mice. Also in the chronic phase, treatment was performed 12 hours before intraperitoneally challenge with 1×106 tachyzoites of the virulent RH strain of T. gondii in rats. One week (in acute phase) and two months (in chronic phase) after post infection, tissues were isolated and DNA was extracted. Subsequently parasite load was calculated using Q-PCR. In acute phase, in both groups, significant anti-Toxoplasma activity was observed using propranolol (P < 0.001). Propranolol in pre-treatment group showed higher anti-Toxoplasma activity than propranolol in post-treatment in brain tissues displaying therapeutic efficiency on toxoplasmosis. Also, propranolol combined with pyrimethamine reduced the parasite load as well as significantly increased survival of mice in pre-treatment group. In the chronic phase, anti-Toxoplasma activity was observed with propranolol and decreased parasite load in tissues. In conclusion, the presented results demonstrate that propranolol, as an orally available drug, is effective against acute and latent murine toxoplasmosis at low doses and increase efficiency of drug in combination therapy with propranolol-pyrimethamine.