The identification of parasites in ancient human faeces is compromised by differential preservation of identifiable parasite structures. However, protein molecules can survive the damage of the environment and can be detected even after centuries. In this paper it is shown that is possible to detect copro-antigen of Entamoeba histolytica in historic and prehistoric human faecal remains, using a commercially available enzyme immunoassay (ELISA) kit. The kit uses monoclonal antibody-peroxidase conjugate specific for E. histolytica adhesin. A total of 90 specimens of desiccated faeces found in mummies and ancient organic sediment from South America, North America, Africa, and Europe were examined. The ELISA detected 20 positive samples, dated to about 5300 years before present to the 19th Century ad. The positive samples are from archaeological sites in Argentina, USA, France, Belgium, and Switzerland. The detection of protozoan antigen using immunoassays is a reliable tool for the studies of intestinal parasites in the past.