Background. - Because of the risk of hemorrhagic disease of the neonate secondary to vitamin K deficiency, it is generally agreed that neonates should be given vitamin K. There is however, no consensus concerning the route of administration, dose, number of doses, or dose frequency. It was therefore necessary to determine patterns of vitamin K administration in France. Population and methods. - Routine vitamin K administration was studied in 1993 by questionnaires sent to all maternity units in France. Results. - Six hundred and forty of the 1086 questionnaires could be analysed. Vitamin K was never prescribed in 0.3% of maternity units and was given only to high risk neonates in 3%. In healthy neonates receiving milk formulas, the route of administration (oral or IM) agreed with the recommendations of the French Committee of Pediatric Nutrition. In contrast, breast-fed infants were given IM vitamin K in only 19% of the matenite' units whereas regular weekly doses were prescribed in only 56%. In premature infants, IM doses were prescribed in only 46% of cases and repeated weekly doses in 34%. The dose generally prescribed (5 mg orally or IM) was not the recommended dose. Among the available products, oral or parenteral vitamin K Roche(R) was the most frequently prescribed. Conclusion. - New recommendations for the use of vitamin K in the perinatal period in France are necessary.