Generalised recessive dystrophic epidermolysis bullosa (EB) is a severe inherited disease leading to scarring and mutilation of the skin and mucous membranes. Prenatal diagnosis has been performed using fetal skin biopsy at 15 weeks gestation. Cloning of the type VII collagen gene (COL7A1) and identification of informative intragenic markers enabled demonstration of tight genetic linkage between recessive dystrophic EB and COL7A1 in two independent studies, with no evidence of locus heterogeneity. Prenatal diagnostic exclusion of recessive dystrophic EB has recently been reported using fetal DNA from an at risk pregnancy. We describe our experience of prenatal diagnosis using informative COL7A1 markers. The first child of consanguineous parents was affected with severe recessive dystrophic EB. Electron microscopy of skin demonstrated a lack of normal anchoring fibrils and indirect immunofluorescence showed a marked reduction of type VII collagen expression. A chorionic villus biopsy was obtained at 10 weeks gestation in a subsequent pregnancy and DNA extracted. A PCR-based test for an intragenic COL7A1 PvuII polymorphism was performed on the chorionic villus sample as well as the other family members. This was fully informative and indicated that the fetus was unaffected (heterozygous). The flanking marker D3S2 was partially informative, being heterozygous only in the mother, and helped to exclude maternal contamination of the chorionic villus sample. This study shows that rapid prenatal diagnosis can be performed early in pregnancy in families informative for COL7A1 markers.