Pregnancy during adolescence can be considered a health problem because it involves a greater risk, according to the WHO, for the health of mother and child. In this retrospective study an analysis was made of the socio-economic profile and the evolution of gestation and delivery of adolescent mothers attended by the Virgen del Camino hospital. A differentiation was made between two groups, with ethnic origin (Caucasian/Gypsy) taken as a variable, since it was considered that this determines the outcome of pregnancy. It was concluded that a high percentage had a partner and were under obstetric supervision and, probably for this reason, had had spontaneous deliveries, with a low index of prematurity. An association was also drawn between precocious maternity and urban environment or academic-occupational inactivity.