In order to test what could be justification for external cephalic version (ECV) in breech presentations, the authors carried out a prospective study in the four university maternity units throughout the year 1989. This brought together 262 breech presentations of more than 30 weeks duration. They compared the results in two units where ECV is carried out frequently with two where it is carried out rarely. Comparing the two groups there was very little difference in the incidence of breech presentation at the onset of labour after 36 weeks (the difference being 33.6%). An analysis according to the parity of the mothers however shows that for primigravidae there was very little difference, but is was a little above 50% in women who were low grade multi-gravidae. Incidents or accidents connected with ECV were very rare. The discussion centres more on the values to the mother and the fetus than at the level of the obstetrician himself. From this study and the reflections on it, there is no single feature that shows in the present circumstances anything for or against ECV. This is because although there has been a large multicentre study they have not compared the maternal/fetal prognosis after 36 weeks of vaginal breech delivery and Caesarean delivery as compared with those deliveries for cephalic presentations. Only a study like that could make it possible to respond to the basic question whether ECV is justified and what attitude should be taken when it fails as far as delivering the breeches that remain is concerned.