Background: Diagnosis of toxoplasmosis relies mainly on determination of IgG and IgM using ELISA. However, inter-laboratory evaluation of performance of many commercial kits gave unsatisfactory agreements. Merging the innovative use of quantum dots nanobeads (QDNBs) immunoassay may yield higher sensitivity and specificity than the conventional used methods. Objective: The present study aims to evaluate the performance of QDNBs based immunoassay in serodiagnosis of human toxoplasmosis. Subjects and Methods: The study included 175 subjects divided into three categories; 122 patients with clinical manifestations suggestive of toxoplasmosis; 32 patients proved positive for other parasitic infections, and 21 healthy control subjects. In comparison to Sabin Feldman dye test (SFDT), as a gold standard test, serum samples were examined in an immunoassay utilizing QDNBs for detection of T. gondii specific IgG and IgM antibodies. Results: Compared to SFDT, combined QDNBs-IgG/IgM immunoassay exhibited sensitivity of 95.4%, specificity of 98.9%, positive predictive value (PPV) of 98.8%, and negative predictive value (NPV) of 95.6%, with relative agreement, validity, and accuracy of almost 97%. Conclusion:It was concluded that QDNBs-based immunoassay improves the performance of ELISA particularly sensitivity as well as shorten the assay time. QDNBs for diagnosis of toxoplasmosisAbd El-Ghani et al.,