The purpose of this study was to evaluate the rationality of congenital syphilis (CS) cases reported by physicians in hospitals of various levels in Guangzhou, China. The over-reporting rate was calculated. The results suggested that 49.1% (54 out of 110) of the CS cases reviewed were identified as cases that should be reported; 18 of the 54 CS case were confirmed CS cases and 50.9% (56 out of 110) were identified as over reported. Factors associated with CS case misclassification were analysed. To decrease the incidence of CS, antenatal care management and rapid plasma reagin titres should be provided and the follow up for children should be raised.