The aim of this study was to describe knowledge about and use of emergency contraception (EC) among Danish women requesting termination of pregnancy. The study included 1514 women (response rate 83.7%) referred during the period August 2000 to May 2001. Sufficient knowledge of EC was defined as knowledge about both the correct time limit and where to acquire the EC. We found adequate knowledge in 44.7%. These women were typically younger, better educated and more often singles, nulliparae, and users of contraception. No relation was found to the type of contraception used or to previous terminations of pregnancies. EC was used in the actual pregnancy by 6.6% and 24.1% had used it previously. Actual or formers users were characterized in the same way. The general knowledge about EC has not improved significantly during the last few years and there is still need for information about the correct use of EC.