Background: Toxoplasmosis represents a neglected equatorial poverty disorder triggered by an intracellular mandatory protozoan parasite, known as Toxoplasma gondii. Aim of the work: Purpose of this study was to assess the Effectiveness of Toxoplasma Surface Antigen Grade I for Diagnosis of Human Toxoplasma gondii in Egypt by Sandwich ELISA Technique. Subjects and Methods: This study was conducted on 94 individuals, divided to 3 categories, category I: Toxoplasma gondii, category II: Other parasites, It encompassed 10 infected patients that have E. histolytica and 14 infected with G. lamblia and category III: Healthy control group. Result: The cutoff value was 0.233 when detecting Toxoplasma (SAG1). The serum findings appear positive in 43 cases (86 per cent) of category I, whilst 7 cases (14 per cent) appear negative. In category II (patient with different parasites): 10 positive cases of Entamoeba histolytica have been confirmed, while other 14 cases were positive with G. lamblia. All healthy control cases (category III) were negative. The sensitivity was 86% However; the specificity was observed 81.81%. Finally from the obtained results, we can conclude that: to evaluate the different immunodiagnostic antigens detection assays, choice and purification of the suitable antigen, accompanied by the manufacture and purification of its particular antibodies, are mandatory. The employment of rabbit anti-Toxoplasma gondii IgG polyclonal antibodies in sandwich ELISA techniques for identification of SAG1 in human serum provide a sensitive and specific tool for immunodiagnosis in human toxoplasmosis. Keywords: Toxoplasma gondii; diagnosis; ELISA; Human toxoplasmosis; blood; patients.