the toxoplasma gondii detection in venous blood and placenta of pregnants by polymerase chain reaction may facilitate the diagnosis of congenital toxoplasmosis. we evaluated pregnants with reagent immunoglobulin m (igm) and their children. beyond serological toxoplasma-specific immunoglobulins g (igg), m (igm), a (iga) and igg avidity (meia), we did immunoperoxidasis and mice inoculation. genomic amplification with gene b1 primers and new tgr primers (called abgtg7 c1 and n1) was conducted for each sample. it's necessary to observe that treatment probably is responsible for the infection decrease, that manner, negative results would confirm uteri therapeutic efficiency. pcr was sensitive and specific, it identified one to ten tachyzoites. besides being a fast form of congenital toxoplasmosis diagnosis, it may be used safely and trustly, as an important tool for congenital evaluation.