Dientamoeba fragilis is a human intestinal protozoon. Its worldwide prevalence ranges mostly between 1.4% and 19%. Very little is known to date about its virulence, pathogenicity, and mode of transmission; and no cyst stage has been identified yet. A wide spectrum of gastrointestinal symptoms has been described in a great number of infected patients: diarrhoea, flatulence, colic, and weight loss, amongst others. The simultaneous association between infections with D. fragilis and those caused by Enterobius vermicularis lead Burrows and Swerdlow in 1956 to speculate about the probable role of pinworm eggs in transmission. This work is the first attempt to detect the presence of D. fragilis DNA on the outer shell of E. vermicularis eggs, by means of a DNase assay and posterior identity verification by means of a restriction digest analysis of PCR products with HinfI, in co-infections with both parasites. Enterobiosis is extremely prevalent in human beings worldwide. In paediatric patients with direct evidence of pinworm infection, the search for D. fragilis should be enhanced