Technical and biological aspects of contraception are discussed and their relations with important demographic variables such as mortality, fertility, and marriage rates are analyzed. In France (and in Eurpope generally) contraception does not seem to have resulted in fewer illegitimate births or premarital conceptions. It does not appear to have contributed to a lower age at marriage, or to increased numbers of marriages. Some deaths due to pregnancy or illegal abortion may have been prevented by contraception. It does not seem to have been a factor in sexual liberation or in the decline in fertility, which was evident before contraception was legalized in France.