A prospective study of 78 pregnant women was undertaken to detect maternal enterovirus infection. Maternal faecal especimens and blood samples, placental and fetal tissue were taken for viral study, electron microscopy, histochemistry, and morphological examination. We present the post-mortem findings in three fetuses whose maternal infection was detected before delivery by isolation of ECHO virus type 33 and type 27 from faecal specimens and/or placental and fetal tissues. The morphological aspects were similar in all cases and included an acute infection of the placenta and hypoxic/hypotensive injury to fetal organs. In one case, viral particles were detected by electron microscopy of the fetal liver. This series of cases of intrauterine ECHO virus infection confirms the potential gravity of such infection during pregnancy and the need to prevent enteroviral disease.