The birthrate has decreased for all age groups except for adolescents. 4.51% of all pregnancies in Spain fall within the 15-19 year old age group. The prevention of adolescent pregnancy indicates the need for making family planning services more accessible to young people. The object of this study was a review of medical consultations performed in 1993 with adolescents at a family planning service. Among the most significant results are the following: the average age of menarche and coitus primaris was 11.8 years (+ or -2.2 years) and 16 years (+ or -1.7) respectively. The period between coitus primaris and the act of going to a family planning center was 9.1 months (+ or -2.3). 81.7% of those adolescents were advised to take oral contraceptives, 12.4% condoms, 1.96% the I.U.D. and 3.9% none. Among the most common side effects noted after taking oral contraceptives for 6 to 12 months were: psychic alterations (changes of mood, etc.), spotting, digestive upset, migraines and weight increase. The number of sexual partners before and after contraceptive use did not change significantly.