The authors analyse, in the context of a developing country, a number of factors which can determine the choice of site of delivery in a population with access to several possibilities. The role of peripheral (or local) maternity units is considered in particular, in view of the utilisation problems which they raise. This leads to the conclusion of a degree of irrationality in the choice of health care services and the characteristics of women interacting with those of professionals when explaining the choice of site of delivery. Better management of available services is desirable in order to render peripheral maternity units more useful, and improve the medical performance at the time of delivery. Sensitization of the public and above all of health professionals nevertheless remains essential.