The cellular distribution (localization and quantitation) of the target parasite's antigens in the tachyzoite along the IgA kinetics was determined in the course of acquired toxoplasmosis and congenital toxoplasmosis. In the case of acquired toxoplasmosis, throughout the IgA kinetics a correlation was noted between the membrane and submembrane immunolabeling and the results of the immunocapture and enzyme-linked immunosorbent assay IgA (ELISA-A) tests. The rhoptries' immunolabeling remained higher. The immunolabeling evolution and the results of the immunology tests were not closely related to the treatment (Rovamycin). From the congenital toxoplasmosis cases it was observed that membrane immunolabeling correlated with the results of the serology tests and with the treatment (Fansidar). The rhoptry antigens were recognized throughout the IgA kinetics; even when the serology tests became negative, immunolabeling persisted. Rhoptries appeared as secretory organelles of antigens recognized during acute, chronic, and congenital stages of Toxoplasma infection.