Intestinal parasites are highly prevalent in tropical areas and developing countries, but are also common in industrialised countries as well. Traditionally, their diagnosis has been made by microscopic examinations of the faeces of the patient. These have been shown to have poor sensitivity, require serial samples, are very time-consuming and require a specialised technique. In the last few years, advances in the molecular biology of these parasites and research into the specific immune response of the patient, has made it possible to develop more efficient detection systems that help the clinician, allow treatments to be followed up and make it easier to carry out epidemiological studies. Among these systems are the methods for detecting faecal antigens, which, in general, have good specificity and sensitivity; properties which make them a useful tool in microbiology laboratories.