This study, based on the Lebanese National Perinatal Survey which included 5231 women, examined the relations between the caesarean section (CS) rate and the characteristics of mothers, children, antenatal care and maternity units in two geographical zones of Lebanon (Beirut-Mount Lebanon and the rest of the country) and then looked at geographical variations. This analysis concerned 3846 women with singleton pregnancies and livebirths at low risk of CS, after exclusion of women with a previous CS, non-cephalic fetal presentations, or delivery before 37 weeks' gestation. The principal end point was caesarean delivery. The relations between the factors studied and CS were estimated by odds ratios (OR), both crude and adjusted, using logistic regression. The rate of CS was higher in the Beirut-Mount Lebanon zone than elsewhere (13.4% vs. 7.6%). After adjustment, several factors remained associated with caesarean delivery in each zone. Common factors were primiparity, gestational age > or = 41 weeks and antenatal hospitalisation. Factors identified only in the Beirut-Mount Lebanon zone were obstetric history and insurance coverage, whereas for the other zones we only found major risk factors for obstetric disease: maternal age > or = 35 years, number of antenatal consultations > or = 4 and birthweight < or = 2500 g. The multivariable analysis of the overall population, adjusting for zone of delivery and other variables, shows that zone was one of the principal factors associated with the risk of caesarean delivery in Lebanon (OR = 1.80 [95% CI 1.09, 2.95]). In conclusion, the CS rates in Lebanon were high, with geographical differences that were associated with access to care and with obstetric practices.