The use of contraception by women 30--50 years of age is presented. The material was composed of participants in the prophylactic investigations for cancer colli uteri in the southern part of Storstøms County, which was first performed in the period 1967--69 and secondly in 1972--74. A total of 17 028 women were examined, of whom 8 234 participated in both surveys. A comparision of the two periods of investigation revealed a significant increase (p<0.01) in the utilization of contraception and in shifting to more effective methods. This improvement was attributed to the increased amount of information about contraceptive methods which was made available in the country. It was observed that a remarkably large percentage of the women did not use contraception, 24.9 per cent among those 30--34 years of age, 26.9 per cent among those 35--39 years of age, 40.7 per cent among those 40--44 years of age and 57.2 per cent among those 45--49 years of age. Analysis of the influence of socioeconomic conditions showed that women of the lowest social stratum, with slight education and low income, made up a large proportion of those who abstained from contraception. The number of pregnancies was found to play a role in the use of contraception. An expansion of the distribution of information about contraception to the public is recommended, as well as a possible economic subsidy to the socially disadvantaged for procurement of contraceptives.