During the period April 1984-February 1985, 4 test samples of totally 380 young Danish women aged 16–20 years old were invited to interview about contraception and sexual behaviour. The response rate was 75,3%. There were 208 (74,0%) who had had sexual debut. Median age was estimated to 16.8 years. At first intercourse 168 (80.8%) used contraception, 36.5% used condom and 36.1% oral contraception (OC). Among teenage-girls with sexual debut before 15 years old 32.5% were unprotected against pregnancy. At the time of the interview 64.4% did use contraception. The most frequently used contraceptive device was OC (46.6%). Teenage-girls changed the contraceptive method from condom to OC after sexual debut. A small proportion of sexually active girls (8%) did not use contraception neither at first intercourse nor at the moment.