The precise detection of Toxoplasma gondii infection in cats has important public health significance. In the present study, recombinant granule antigen protein GRA7 was evaluated as a potential diagnostic marker for T. gondii infection in cats by an indirect enzyme-linked immunosorbent assay (ELISA), using the classified serum samples from cats, by immunofluorescence assay (IFA) and by modified agglutination test (MAT). There was a perfect agreement (97.2%) between GRA7-ELISA and MAT/IFA (Kappa = 0.92; 95% confidence interval [CI], 0.85 to 0.99), and GRA7-ELISA had a sensitivity of 94.9% and a specificity of 97.9%. No significant difference (P > 0.05) was observed between the detection results by GRA7- and Toxoplasma lysate antigen-based ELISA. Receiver operating characteristic analysis showed a relative sensitivity and specificity of 89.7 and 92.5% at the cut-off value of 0.1 for GRA7-ELISA. These data demonstrate that GRA7 is a promising serodiagnostic marker for T. gondii infection in cats.